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Life as agency


‘We understand and explain life from many perspectives and scales. From our human perspective the most familiar scale is that of autonomous cellular organisms acting on, and reacting to, their internal and external environments. As open and dynamic agential systems, organisms regulate and integrate their flows of energy, materials, and information. This biological agency is unified in the ultimate predisposition to survive, reproduce, and flourish (the biological axiom). This biological axiom is a grounding statement of fact, agency, purpose, and the normativity expressed by all organisms, but only mindfully (in part) by humans.


In the short-term (one generation) agential behaviour occurs over a lifecycle of fertilization, development, maturation, reproduction, senescence, and death. Over the long term (multiple generations) all organisms, as products of natural selection, display species-specific adaptive design and the potential to evolve new forms when heritable variation, transmitted to phenotypes via the chemical DNA, is subject to environmental selection.’

Life, from a human perspective

Our understanding of the universe – its origin, physical composition, properties, and age – has, over the last 150 years, been totally transformed. Our best science tells us that, during the cosmic evolution that followed the origin of the universe at the Big Bang, physical structures – including their properties, and relations – showed the capacity to increase in complexity through a process of emergence as everything, including space and time, evolved from a point source.

Contemporary cosmology

The Steady State theory of the universe and the biblical account of God’s Creation of the world were static and eternal accounts. Before Darwin it was assumed that the universe was either a supernatural creation or had existed for all time. Biological species were immutable, each created individually by God.

Today science depicts our universe in its first moments as undifferentiated plasma but now containing a multiplicity of physical kinds. Complexity has emerged from simplicity. Everything in the universe, though not necessarily graded uniformly from one physical form to another is, nevertheless, cosmically continuous and connected.

The combination of the publication of Darwin’s On the origin . . . (1859), and the replacement of the Steady State Theory of the universe with the Big Bang Theory of its origin in the 1930s, overturned the prevailing scientific worldview. The world no longer consisted of immutable species within an eternal universe. Instead, the universe was physically connected to its point source and now unfolding in evolutionary time.  Darwin showed how all organisms are biologically related to one another in a community of life, while modern cosmology demonstrated that life was, in turn, composed of the stuff of the universe – that all organisms are, indeed, made of stardust.

In a chronometric revolution that has taken place over just a few generations we can now locate humanity within a scientifically verified cosmic, geological, and biological historical timeframe. We can date the age of the universe, individual rocks and fossils, the divergence of lineages and languages, and archaeological remains.

The origin of universe dates back 13.7 billion years, the solar system 4.6 billion years, and life 3-4 billion years. In the last 50 years our understanding of human biological and cultural evolution has been vastly refined. The genus Homo evolved from former Australopithecines around 3 to 4.4 million years ago, anatomically modern humans appear around 315,000 BP, and our more complex cognitive capacities around 100,000 years ago or earlier (perhaps a consequence of language development and sociality as core group numbers increased from 15-20 individuals in nomadic hunter-gatherer societies to about 150, then more. Migration out of Africa occurred about 80-90,000 BP, followed by dispersal across the world, the development of agriculture around 12,000 BP, and the first cities in about 5000 BP.

This recently acquired timeline has allowed us to frame human existence within the scientific cosmic timeline of Big History.

Humans did not suddenly spring into nature as conscious, rational, and biologically supreme rulers of planet Earth. Darwin placed humanity at the tip of one twig – one lineage – of the vast Tree of Life, all connected backwards in time, by the immortality of our genes, to the first rudimentary ancestors of all life.

With this modern scientific worldview of evolutionary continuity and connection in mind, this article revisits the question ‘What is life?’ and philosopher Aristotle’s 2500 year-old idea of life being purposive and agential. A follow-up article on human-talk then examines the similarities, differences, and connections between humans and other organisms (both real and metaphorical) as they are depicted in allegedly anthropomorphic language.

As always, key claims are presented as principles to reflect on and criticize. The principles in this article are not intended as strict definitions, but as clarifications of key terms and ideas presented in the article.

What is life?

In the 1930s an answer to the question ‘What is life?’ seemed an attainable aspiration.  Darwin had provided what was, in effect, a unified theory of biology; but his theory had always lacked a material foundation, a physical account of heredity. After Robert Brown’s discovery of the cell nucleus in 1831 cell theory made major progress in the mid-nineteenth century under the influence of German physiologists Matthias Schlieiden and Theodor Schwann when it was established that all living organisms are made up of cells that are produced from pre-existing cells. That is, cells are both the basic unit of living structures, and the basic unit of reproduction. Then, in the 1880s, chromosomes were experimentally established as the vectors of heredity and it was anticipated that by drilling ever deeper into the physicochemical constituents of matter, we might eventually find the biological holy grail, the physical secret of life.

In part, this is indeed what happened as, in the 1950s, the macromolecules of chromosomes were revealed as constituting a double helix that was, in effect, a genetic code passed from cell to cell under replication, the code being deciphered by biochemists James Watson, Francis Crick, and Rosalind Franklin. Humanity had now discovered how the historical blueprint for every organism, reaching back to its first ancient origins, existed in every one of its cells. At last, there was a material explanation for morphogenesis and the potential immortality of biological kinds.

From another perspective, physicists had noted that organisms were peculiar energy systems.  By a process of self-organization during a lifetime, they built and maintained autonomous biological order against the pervasive external forces of disorder (entropy). This capacity of organisms to temporarily resist the entropy of the universe Austrian-Irish physicist Erwin Schrödinger referred to in his 1944 popular-science book What is Life? asnegative entropy’, an expression later contracted to ‘negentropy’.[19]

The discovery of the structure of DNA was a breakthrough that, at last, provided a compelling material answer to the question of what it was to be a living creature. The genetic code was matter that contained the information needed to create biological structure, function, and behaviour. This was the crucial material account of heredity that had been missing from Darwin’s theory.

As biological molecules come into greater scientific focus, reductionism thrived through the new subjects of biochemistry and microbiology and its many new applications to biotechnology.

The universal characteristics of living organisms[12] currently defy formulation into a neat summary package. Life is too complex, it is assumed. Key characteristics of life are presented as an ever-expanding shopping list of universal properties unearthed by the expanding fields of research.[13] 

This messiness of biological definition could be overcome if one perspective on life were acknowledged as in some way prior to, or grounding, the others. But finding such a perspective seems unlikely when multiple representations are pragmatically differentiated, and disciplines hunker down ever deeper within their academic silos.

From what perspective?

The difficulty in finding a consensual definition of life arises because biology is studied and explained from multiple perspectives or systems of representation (academic disciplines, frames of reference, levels of organization, points of view). This is a problem compounded by ever more sophisticated technology extendng our knowledge of biological systems beyond the scale of our human senses, into the micro- and macro-realms.

However, out of this growing body of scientific knowledge a new scientific paradigm is emerging.

There is now resistance to the once-favoured physical reductionism that increased in popularity after the 1930s and gathered momentum with the subsequent molecular research. This view is starkly expressed by Duke University philosopher Alex Rosenberg who claims that ‘physical facts fix all the facts’ and that physical facts reduce to fundamental material constituents . . .  ‘roughly speaking, fermions are what matter is composed of, while bosons are what fields of force are made of[25] and therefore ‘What ultimately exist are just fermions and bosons and the physical laws that describe the way these particles, and that of the larger objects made up of them, behave‘.

This reductive paradigm is associated with the idea of the unity of science founded on our analytic understanding of physics and its particulate constituents , which therefore constitute ‘reality’. I call this particular perspective ‘smallism’ because it appears to be motivated by the belief that the most effective scientific explanations must proceed by analysis. Only by looking at simple parts (regarded as foundational and fundamental) can we unleash the secrets of more complex wholes.

A contrary view expressed here (sometimes called aspect theory or perspectivism), acknowledges that everything biological must be physical, but denies that biological truths must be physical truths . . .  there is no necessary physical reduction. From a holistic perspective, wholes have their own aggregate novel properties and relations that arise as part of the process of emergence.

We investigate the world through multiple systems of representation of equal validity and whose representational efficacy is pragmatically determined. There is no ultimate physical reality that we can articulate: ontology itself is perspectival. Nothing in the physical world is more ‘real’ (fundamental) than anything else: a boson or fermion is no more ‘real’ than an elephant or a daffodil . . . or, for that matter, energy, number, or information. There are simply diverse ways of interpreting the world depending on our interests and goals. Each representational system has its own standards and measures of excellence and efficacy often with its own domain-specific principles, procedures, terminologies, and explanatory goals.

In practice, we explain life in terms ranging from global ecology to molecular biology, from physical structures to behaviour and functions, from informational content to its means of communication . . . and much more.[13]  

It is this multiplicity of representational systems that precludes the possibility of ever finding a simple definitional cement to bind together all aspects of the organic diversity we now know as the community of life.


About 2,500 years ago the Ancient Greek philosopher Aristotle (considered the founder of biological science) outlined what he thought distinguished life from other forms of existence. He observed that in nature almost everything was directed towards goals – organisms, processes, structures, functions, behaviour and so on . . . all were invariably ‘for’ something in a way that was not apparent in the inanimate world.

This goal-directedness of things in nature, their orientation towards ‘ends’, Aristotle referred to as telos – the purpose, aim, objective, or ‘final cause’ as he called it. This goal-directed agency, he observed, arose from within organisms themselves: it was not imposed from outside by, say, a supernatural agency, or the human imagination. It was as though every organism contained an ‘inner craftsman’ designing all aspects of that organism’s life for a reason or purpose. ‘Nature does nothing in vain’, he claimed.

Science investigates the orderliness of nature and, for Aristotle, telos was a special kind of natural order that was most clearly exhibited by living creatures. The integration of parts, processes, and behaviour produced a whole organism functional autonomy. This autonomy is intuitively expressed in human-talk through the word ‘self’ and the independent agential properties of self-organization, self-regulation, self-replication, and self-preservation. Though the proximate ends of organisms are many, ultimate ends crystallize into a unity of purpose that is shared by all living things – the predisposition to survive, reproduce, and flourish.

The Scientific Revolution

Aristotle’s observations on purpose in nature, and his doctrine of final causes, all lost favour during the Scientific Revolution (c. 1550 to 1750) as a new breed of thinkers questioned ancient authorities. Aristotle’s ideas, especially, were attacked as part of the process of scientific rejuvenation. Old ideas needed to be challenged if science was to move forward and, as scientific knowledge advanced, it was not difficult to demonstrate empirical errors in Aristotle’s thinking. Emphasis on experiment and observation now downplayed Aristotle’s deductive logic and obscure philosophical ideas.

Intellectuals of the European Renaissance and Enlightenment (impressive authorities like Bacon (1561-1623), Descartes (1596-1650), Spinoza (1632-1677), Hume (1711-1776), and Kant (1724-1804)) all thought that the purpose Aristotle saw in nature, its teleology, was making the old mistake of imbuing unconscious nature with conscious intentions. Telos sounded like a new way of referring to the same old mysterious supernatural forces of the past, but this time arising within organisms in a vitalistic way, rather than being instilled from without by a supernatural agency.

This view of telos was reinforced by the obvious way that our metaphorical biological language often imbues non-conscious organisms with conscious intentions. Telos was too abstract: it had the ring of a mysterious and unnecessary internal supernatural vitalistic forces that were not amenable to the newly invigorated empirical mode of enquiry.

Can agency provide a focus or key defining criterion of life that is easily understood while minimizing the problems associated with perspective and scale?

Let ‘s look more closely at what is entailed by the claim, expressed in human terms, that every organism is an agent on a mission – beginning with a clarification of three key elements: the agent, the mission, and the means of attaining the goals of the mission.

Principle 1 – Agency has three key components: an agent, its mission, and its means of pursuing that mission

Principle 2 – an agent has the capacity to act and react; it is the instrument or means by which a purpose is pursued

Principle 3 – A purpose is the reason (end, aim, or goal) why something exists or is done, made, used etc.


What do we mean by agency . . .  where does it come from, what is to count as an agent and, more specifically, what is the role of agency in nature?

Agency is a graded concept with an agent of the simplest and most generalized form being, say, a cause that brings about an effect. At the other extreme there are the complex intentional actions we associate with human activity.

Through history there has been a longstanding philosophical battleground over the source of agency in the world: is it derived from God, physical nature, biological nature, humans, or some combination of these? The prevailing scientific view is that nature has no real agency, purpose, or design.


Historically, the notion of agency has been strongly linked to supernatural forces of various kinds and this accounts, in part, for today’s inherited scientific suspicion and resistance to the notion of agency in nature.

Nature is full of powerful and terrifying forces (agencies) that can change the face of the Earth. Earthquakes, tsunamis, storms of thunder and lightning, fiery conflagrations, floods, plagues, famines, and disease.  Why do these terrifying catastrophes happen, and why must humans suffer their consequences?

In prehistory humans imbued all of nature with supernatural agency, not just those forces that threatened their lives. Forests, streams, mountains, trees, and landscapes were populated by spirits, demons, and supernatural animistic forces of many kinds. Gradually, over time, the numbers of these supernatural beings diminished, and supernatural belief focused more on Gods. At first there were many (polytheism) but, eventually, and over much of the world, just one (monotheism). Gradually Gods too became more distant. In ancient Greece they lived high above the world at the tip of Mount Olympus. In later civilizations they departed this world altogether, ascending into the sky to become ethereal, eternal, and ineffable, and eventually completely dissociated from space and time. Even today, most people in the world regard a supernatural agency as guiding what happens in the world.

Perhaps there were always a few people with a scientific cast of mind who doubted that these supernatural agents ever existed. Maybe these forces, both beneficial and destructive, arose within nature itself.


That there are non-human forces at work in the world cannot be denied, but science has endeavoured to provide a naturalistic account of these forces. Agency, as the capacity to act and react, is a manifestation of power, force, drive, or motivation. Science has always struggled with the intangibility of natural forces, even those of foundational physics. Newton accounted for the effects of gravitation while refusing to speculate on what it was, and only relatively recently have we come to grips with phenomena like magnetism, electricity, and sexual attraction.

We have avoided the kind of agency we observe in non-human organisms because, historically, any hint of a ‘life force’ has implied vitalism and a return to the old non-empirical supernatural demons.

Aristotle believed, that telos, the force-like goal-directedness of living things, had nothing to do with Gods, nor was it a reading of our human intentional point of view onto nature. The agency we see in nature, he believed, arose in nature itself. Scientists from the Scientific Revolution on have disagreed until Darwin demonstrated that the purposive drive we see in organisms does, indeed, arise in nature in a scientifically accountable way. Those who continued to disagree, and there are still many, accounted for life’s agency by treating it as a manifestation of that agency with which we are most familiar – our own.

Agency in nature is only ‘apparent’ agency, it is not real. We see similarities between our activities and those of organisms – but these are not real similarities because only humans and their conscious intentions are real and, since organisms do not have conscious intentions, their agency is not real.

It follows that the agential language we sometimes use to describe the behaviour of organisms is only metaphor – the ‘as if’ language of anthropomorphism, and what we might be tempted to treat as agential behaviour in organisms is only ‘agent-like’.


We see the world from a human perspective – how could it be otherwise? We therefore have an anthropomorphic cognitive bias in the way we interpret the world in human terms.  It is hardly surprising that the Gods and spirits of both past and present have taken on human forms and behaviours. The personification and anthropomorphization of nature . . .  the river flowing down a mountain ‘wishing for the sea’, the thunderous voices of angry Gods . . .  these are a reading of human traits into non-human nature, straightforward cases of metaphor.[8]

Aristotle had seemingly perpetuated this cognitive bias by using the word telos to indicate the ‘purposes’ or goals that drive organisms and natural processes.

This is still the prevailing scientific view. The ‘purpose’ we see in nature is added by our own minds; it is a reading of our own intentional nature into non-intentional organisms. Put simply, the purpose we see in nature is not nature’s purpose (nature cannot have purposes), it is our human projection. It is only ‘as if’ nature has purposes and goals. The purpose we see in nature is just a continuation of personification, a metaphor: just a useful human way of thinking about nature . . . a convenient shorthand or façon de parler that makes nature seem somehow closer to ourselves. In recent times, teleology has been treated as a convenient argument for modern-style religious belief and arguments about intelligent design.

The inherited certitude of thinkers of the Scientific Revolution is now under question. It is possible that, in their enthusiasm to rid science of superstition and human subjectivity, they went too far.

Darwin’s theory of evolution achieved two outcomes whose consequences are yet to be absorbed into the body of biological thought – both have a bearing on the question of natural agency:

First, in spite of the biological use of metaphorical and anthropomorphic language (referred to here as human-talk), Darwin nevertheless naturalized Aristotle’s telos by demonstrating how natural selection gives rise to functional adaptations (purposive attributes) in a scientifically accountable and mechanical way. He demonstrated that purpose in nature is ‘real’, it is not confined to human minds.

Second, a finding whose philosophical consequences have not yet been fully realized, he replaced the old idea of discretely created species with a new notion of organic connection and continuity.

These two findings are yet to take up residence in the philosophy of biology as part of our scientific metaphysics.


Darwin immortalized natural ‘selection’, and Richard Dawkins christened ‘selfish’ genes. Both men believed that intelligent readers would understand that they were using language in a figurative way. Biological scientists today still use language that is richly anthropomorphic: human-talk is rife.  We just cannot help ourselves. Is all this just cognitive bias?

Humans are agents because they demonstrate intentional (goal-directed), conscious, and rational behaviour. Can other organisms be agents?

This is not just a semantic quibble. What is at stake is our metaphysical assumption about what is real in nature. Is the ‘agency’ we see in nature superimposed on nature by our minds as metaphor, or is it real? Are we entitled to call an organism an agent, or is doing so just a figurative linguistic embellishment?

It is argued here that since evolutionary theory treats the world as composed of graded biological forms, so the concepts and language we use in relation to these forms must follow the same graded form. Where there is biological continuity there must be conceptual continuity too.

But what does this mean?

Conceptual continuity – fuzzy categories

We like our ideas to be clear and distinct. Communication is simplified when things are straightforwardly true or false, real or unreal, fact or metaphor.

But sometimes physical properties in the real world are not just present or absent, and statements about them true or false. Rather, they exist in nature by degree. We see a rainbow and find it convenient to speak of its discrete colours when, in nature, colour is a continuum of wavelength.

From an evolutionary perspective the community of life is what might be called an interrupted organic continuum. Although it is the consequence of a physical continuum in time, we humans find it convenient to discriminate the differences we associate with individual species. We humans look similar to apes, much less like whales, and nothing like plants. Even so, our common biological heritage means that we humans actually share many genes with our plant cousins.

Gradually we are becoming accustomed to the idea of biological continuity.  Nowadays we accept that humans are animals: before Darwin such a suggestion would have raised eyebrows. Similarly, the idea of a plant or animal exhibiting ‘agency’ – the contention that agency is continuous in nature – becomes problematic for those who wish to treat humans as unique by, say, claiming that the notion of agency must be restricted to agents with conscious intentions.

Another example of a shift in our understanding of a biological concept would be today’s attitude to consciousness.

We now recognize that, in nature (in ‘reality’) consciousness exists by degree. Domestic animals have consciousness, even if it is different from ours. But what about fish? Surely fishes are conscious in some way, and maybe worms? It could even be that we humans have degrees of consciousness throughout our lives, and maybe across a single day. In short, our understanding of what we mean by ‘consciousness’ has become much more fluid in recent times.

If we regard consciousness as a strictly human property, then it cannot be present in other organisms. Whatever other organisms have, it is not ‘consciousness’, it is something different. Now, if we want to be scientifically precise, what word are we to use to designate ‘fish-consciousness’, ‘dog-consciousness’, ‘worm-consciousness’, and other gradations of consciousness? We do not have the technical scientific vocabulary . . . and so we fall back on simply calling it ‘consciousness’ and regarding this linguistic device as metaphor.

This presents a dilemma. Is consciousness real and continuous in nature, or is consciousness a strictly human property and hence metaphor when applied to non-human organisms?

 Principle 4 – Human-talk leaves us with two options: either we can assume that what it denotes is categorically distinct from its relata in the natural world (which are then treated as figurative, metaphorical, and unreal) or we accept that the relationships are real in nature but vary by degree according to the evolutionary relationship (organic composition, complexity, and evolutionary connection) of the organisms being compared

 Principle 5 – Principle 4 offers two ways of providing greater scientific clarity to human-talk. Either, a more precise technical language (as was done with physical structures). Or an acknowledgement that the terms of human talk are being used in an extended sense (i.e. graded in relation to the human circumstance)

Principle 5 expresses the way that, at present, the use of human-talk indicates a lack of technical vocabulary. Of course, this situation also occurred in the history of structural biology which subsequently built up its technical vocabulary. Naturalizing human-talk in this way is an unlikely project. A more productive approach is to naturalize human-talk by acknowledging the reality of evolutionary connection, that both physical and mental characteristics have evolutionary precursors.

Human-talk has various idioms and this is discussed in more detail in the article to follow. For the time-being it is simply noted that the word ‘agency’ as used here as an example of a graded concept. ‘Agency’, as mentioned, may be as simple as cause and effect or as complex as human intention. By these lights the use of ‘agent’ in relation to living organisms is uncontroversial.

Semantic breadth

One reason for conceptual fuzziness is that we use some words with a wide range of meaning. For example, organs of locomotion may have evolved in different ways in different parts of the animal kingdom such that biologists have coined technical terms to differentiate between them. Even though precise technical terms are now available, it is scientifically acceptable to use the word ‘leg’ in this generalized sense meaning ‘organ of locomotion’ – whether it be applied to humans, insects, crabs, molluscs (which also have ‘feet’) and so on. The word ‘leg’, used in this highly generalized way, might be rejected by some people, and in some contexts: indeed, it might well be regarded by some people as an example of anthropomorphism (the legs of insects are very different from human legs). Nevertheless, such generalized usage is currently scientifically acceptable.

We can refer to words like ‘leg’, which might be used in both narrow and broad contexts, as exhibiting ‘semantic breadth’. This will be discussed in more detail in the article on human-talk.

Mindless agency

Humans are perched at the tip of one branch of the evolutionary tree of life. Our physical and psychological characteristics merge into those of our evolutionary relatives by degree.

Only humans understand why animals have eyes, fish have fins, and cacti have spines. This is because humans are reason-representers (Dan Dennett). But because we represent these reasons in our minds does not mean that the reasons and purposes we observe in nature exist only in our minds. Reasons and purposes also exist in nature.

Our emphasis on human conscious deliberation, we are coming to realize, is an overemphasis. We have ignored the fact that organisms are ‘competent without comprehension‘ (Dan Dennett), ‘for without foresight‘ (Roger Spencer), they have ‘knowledge without knowing‘ (David Deutsch).[30]

These insights are just a beginning. There is also ‘memory without remembering‘, ‘normativity without morality’ and more. The use of human-talk will help us understand what is going on here. The genome brings a physical ‘memory’ to the present-day world. Natural selection then adds ‘reason’ as a process of ‘self-correction’ which is the ability to ‘learn’ from past mistakes in a mindless form of ‘anticipation’ . . . the capacity for ‘foresight’. In combination, these physical factors give nature mindless purpose and agency. We intuitively recognize the connection between all these factors and those in our own intentional human lives.

The claim that competence, foresight, knowledge, memory, normativity etc. are fuzzy categories (present in nature by degree) will be unpacked later as part of the investigation into human-talk. For now it is noted that collectively these properties combine into what we know as ‘agency’. This is not the human agency we associate with conscious intention, it is mindless agency. But it is agency, nevertheless, because ‘agency’ is itself a fuzzy category.

We are more closely connected to nature than many of us care to admit. In the wonder we feel for the miracle of our conscious awareness and the rational faculty that has helped our species dominate planet Earth, we can nevertheless underestimate the mindless ‘purposiveness, creative imagination, and rationality‘ that exists, by degree, in mindless nature. Remember, it was this mindless nature that gave us (that created) our brains, consciousness, and reason.

We now need to unpack the human talk that investigates the ‘means’ by which every organism is an ‘agent’ on a ‘mission’.

Principle 7 – ** Only humans are aware of the agency goals of pursued by non-human biological agents. But mindless goals are not non-existent goals – they are not goals that only exist in human minds – they are real in nature. Similarly, the agency that exists in organisms is real in nature. Biological goals can only be understood by human minds, but that does not make them a creation of human minds

The Agent

Accepting ‘agent’ as a graded concept it remains to outline what it means to be a biological agent (actor).


Organisms – unlike rocks, chairs, and dead bodies – are not indifferent to circumstance: they do not respond passively to their inner and outer conditions. It is their capacity to act and react as integrated wholes that gives them agency. This autonomy is an independence of activity that, for convenience, we refer to in human-talk as a ‘self’ . . . the agential autonomy of self-regulation, self-organization, self-replication, and self-preservation. Clearly, in common parlance selfhood too is a fuzzy and continuous concept.

Principle 1 – Organisms are autonomous sources of change as a condition arising from the particular organization (form) of their matter 


As open systems organisms are responsive and flexible, they act and react by integrating their external and internal conditions. Their structures and behaviour manifest functions, aims, or goals that operate over both the short and long term. As open systems organisms also interact with their surroundings.

One aspect of organismal agency is the integration of development needed to produce a goal-directed and autonomous mature individual of a particular kind. This includes the self-regulation (homeostasis) needed to maintain a conducive internal environment in the face of varying external conditions.

Over the short-term organisms process, regulate, and integrate their flows of energy, information, and materials. Inputs from the environment include materials as a source of energy (food), and stimuli that are accessed by a sensory system. Internal processing includes the metabolism needed for the lifecycle of growth, maturation, reproduction, senescence, and death. It also includes the processing of both internal and external sensations. Outputs include material waste, energy, and behaviour that demonstrates both action and reaction to circumstance.

Over the long term, survival and perpetuation is achieved by descent with modification as a result of heritable variation and differential reproduction among replicating individuals (natural selection).

Principle 5 – As agents, organisms are self-replicating open systems with the capacity to regulate the internal and external exchange of energy, materials, and information that are required for  their autonomous pursuit of goals

These are the most succinct and compelling characteristics of the agency that distinguishes life from the inanimate world; the key features that make an organism different from a rock or a chair.

The description of life lies not so much in the variety of its functions, processes, and material composition but that, collectively, they display a unity of purpose (principle 2).

Principle 6 – Biologists, of necessity, investigate the parts of organisms in terms of their contribution to the integrity of the whole as a unified agent. In the absence of purpose and agency biology is just a collection of dissociated facts about the world with organisms treated in the same way that we treat inanimate matter.

The word ‘agency’ gathers emergent meanings and properties depending on the biological agent implied. Human agency brings with it (among other things) the advanced agential characteristics of conscious deliberation.

Principle 7 – Only humans are aware of the goals of pursued by non-human biological agents. But mindless goals are not non-existent goals – they are not goals that only exist in human minds – they are real in nature. Similarly, the agency that exists in organisms is real in nature. Biological goals can only be understood by human minds, but that does not make them a creation of human minds


Organismal reproduction is a cycle of birth, growth, maturation, reproduction, senescence, and death which Aristotle referred to as partaking in the ‘eternal and divine’. He was referring to the way that species, like gods, are potentially eternal, passing on their unique characteristics from generation to generation. Biologist Richard Dawkins refers to this as the ‘immortality of our genes’.

The mechanism of heredity was unknown to Darwin. We now know that it occurs via hereditary material (genes est. late 19th century by Gregor Mendel) that are found in the chromosomes in the nucleus of every cell. The structure of hereditary material of DNA as a double helix of nucleic acids was discovered in 1952, then the pathways of transcription of genetic information from DNA to RNA and protein and the enzyme formation needed for metabolism. All of this is carried out along a backbone of life-supporting carbon molecules.

Replication is accompanied by small heritable variations that result in differences of ‘fitness’ of offspring and this, over many generations of differential reproduction, results in evolutionary change.

Self-replication combined with self-maintenance and modification is sometimes referred to as autopoiesis.

The Mission

So far we have found that biological agents are autonomously active operational units – initiating, influencing, and integrating the events that occur both inside and outside themselves. Clearly life is more about process, change, and behaviour than it is about substance[24] as each organism pursues its own goals in its own way . . . to acquire food and mates, avoid predators etc.

When comparing the animate to the inanimate it is immediately apparent that organisms manifest a unified and purposeful autonomy that is not present in a rock or a dead body. Metabolic processes are themselves sufficient to distinguishes a living organism from a rock.

But, more than this: life has a scientifically investigable order that is different from the scientific order we investigate in inanimate matter. This uniquely biological order is the agency that connects to our own human agency.

Every natural agent pursues its goals through the activity of its body, so the material body can quickly become the focus of scientific attention rather than more abstract property of agency and its goals.

As Aristotle pointed out, the bodies of organisms, and the material out of which they are composed, are not the key features of agency. Bodies are merely the means by which agents pursue their goals or ends. The crucial defining property of an agent is not its matter but its mission (goal, purpose).

Principle 8 – the material bodies of living organisms are subordinate, in explanation, to the goals that they pursue

Proximate & ultimate goals

Organisms, at any given moment, may be occupied with multiple and disparate proximate goals without common direction.

In humans, for example, there are grounding (ultimate) biological reasons (purposes) for behaviour that are manifest in elaborated (proximate) forms. Biologically (ultimately) we eat to live, but proximately we eat for the biological rewards of olfactory and taste stimulation, and the feeling of hunger satiation. Biologically we (ultimately) have sex to reproduce but our (proximate) incentive is the pleasure of physical closeness and orgasm. Though there is a universal (ultimate) biological need to survive, reproduce, and flourish this is manifest in many (proximate) forms.

Though the proximate ends of organisms are many, ultimate ends crystallize into a unity of purpose that is shared by all living things – the predisposition to survive, reproduce, and flourish.


‘Goals’, ‘missions’, ‘purposes’, even ‘reasons’, may be regarded as a form of human-talk. After all, how can a plant have a mission? Even the ‘reasons’ for its structures and behaviour might seem different in kind from human ‘reasons’.

How clear and distinct are these concepts? How straightforward is their semantics? Are these also fuzzy and graded categories?

We can gain some insight into this gradation by examining the notion of purpose.

The word ‘purpose’ is often regarded as a form of human-talk, usually, but by no means always, associated with human intention. This awkwardness is sometimes overcome by, instead, using the word ‘function’. Purpose in nature is discussed in detail in the article on purpose as bioteleological realism.

Agency, as matter integrated into autonomous activity, is indeed like a life ‘force’ that leaves bodies when they die. Today we can account for this goal-directedness in a scientific and naturalistic way.  In human-talk it is like a drive or motivation that establishes a path or direction: it energizes processes and provides the organic dynamism that we describe dispassionately as aims, objectives, and purposes. As a crucial element of agency, goal-directedness (purpose) is also briefly summarized here.

In human-talk, it is clear that legs, arms, eyes, digestion, leaves, roots (essentially all biological structures) are not random occurrences – they serves a purpose. That is, they exist for a reason. Purpose is part of the orderliness of nature.

The biological propensity of organisms to influence events and constrain the range of possible outcomes (by self-regulation, self-organization etc.) – creates ‘directions’ or ‘paths’ for events that can impact on the organism’s persistence (survival). That is, structures, behaviour, and processes of all organisms tend to towards the preservation of the organism.

This pervasive goal-directedness of all aspects of nature he referred to as telos, usually translated to the English ‘purpose’ but interpreted here in a more general sense as ‘agency’. The fact that it is present in most organisms in a mindless and unconscious way that is only evident to humans, does not negate its existence in nature. Certainly, only humans (as conscious and rational purpose-representers) can appreciate agency in nature. But that does not mean that humans create nature’s agency.

A philosophical industry has been devoted to the avoidance of the word ‘purpose’ and its replacement with the euphemism ‘function’ in the mistaken belief that this is doing a service to biology (see, for example, [26][27][28]). ‘Clarification’ of the apparently inapropriate notion of purpose has spawned Selected Effects Theory, Generalized Selected Effects Theory, Etiological Theories, Causal Role Theory, Neo-Teleology, teleosemantics, and various other philosophical prophylactics.

Biologist Richard Dawkins also uses the word ‘function’, diminishing purpose in nature (like Darwin he is possibly concerned that if ‘purpose’ is admitted in biology then God will likely follow) by referring to it as archaeo-purpose, on the grounds that it is not mindful purpose. He nevertheless obliquely acknowledges its central significance, and reinforces the idea of life as agency, by regarding ‘functional complexity’ as diagnostic of life.[29]

Darwin described how eyes, legs, leaves, and spines arose in nature as adaptations that were ‘for’ walking, seeing, light collection, and deterrence. Indeed, it is difficult to find a structure or behaviour in nature that does not have an obvious reason for its existence, one that ultimately relates to the biological axiom. In this way he naturalized purpose and function in nature, and in so doing he grounded teleology (purpose) in nature itself. Purpose/agency was not imposed from outside by either humans or God. Darwin did not remove purpose from nature by explaining it away. The purpose of a prosthetic leg is established by the intentions of its inventor. Legs that occur in nature also have purposes, even though they were created by a natural process that has no conscious intention. Moreover, the idea that purpose in nature demands the foresight that is only present in humans, is simply mistaken. It arises in nature through a straightforward causal process of adaptive feedback of natural selection; it does not require the foresight we associate with consciousness or backward causation. Aristotle’s final causes make sense. Nature can be ‘for without foresight’ and without defying the accepted conventions of science.

In short, teleology is now OK. Biologists need not feel guilty of transgressing an important philosophical boundary when using the language of purpose, agency, and design in biology.

‘Direction’ is instilled in matter through the iterative process of natural selection. An organism contains within its genome both its evolutionary history and present-day potential. It is equipped with the means of reacting to present conditions in ways that enhance its survival.

These ideas are explored in more detail in the articles on human-talk and purpose as bioteleological realism.

Unity of purpose

Biologists and philosophers have long denied that life has ‘purpose’ while, at the same time, proceeding in their research as though the goals of life are self-evident. Read any biological text and you will find the explicit or implicit assumption that life is founded on self-preservation and continuity – survival and reproduction – both within a single generation, and over many generations of self-replication.

The purpose of living organisms is not something that we make up, something that our minds impose on them. The purpose of organisms derives from their own origin and place in the scheme of things – from their inner nature interacting with their outer environment in an expression of agency. Agency is not just the mindful purpose and value inherent in human conscious intention, it is also the mindless purpose (the goal-directed activity) of all organisms, collectively united in the propensity (drive) to survive and reproduce.

Survival and reproduction are the nearest we get to a scientific consensus on the ultimate goals of all organisms although these ultimate ends are pursued indirectly through the proximate goal of flourishing as short-term health and long-term fitness maximization.

This is the unity of shared purpose is, in effect, a biological axiom, a grounding principle for all life.

Biological Axiom – living organisms[12] are biological agents that share a unity of purpose: the predisposition to survive, reproduce, and flourish

The biological axiom

We associate science with the establishment of principles and universal laws, most notably the universal laws of physics. Viewed in this way, biology is then the subset of complex (living) matter that exists within all-embracing physics. The universal law-like statements of physics are like the absolute certainties of mathematics . . .  the dictates of Gods.

Maths is built on axioms – statements that are taken as self-evident, foundational, and uncontroversial. A couple of examples from Euclid’s geometry would be that ‘Things that are equal to the same thing are also equal to one another’ and that ‘All right angles are equal to one-another’. To deny an axiom is to undermine foundations. If we argue that Euclid’s axioms are mistaken then we are, in effect, challenging the entire enterprise of Euclidian geometry.

We respect the empirical generalizations of science (its principles and laws) because they have predictive power and therefore help us manage the world and our lives. Physical constants, the laws of physics, have the properties of axioms because they resist contrary evidence and cannot be altered without transforming our understanding of theoretical foundations.

Can there be axioms in biology?

Well, if there are axioms in biology then, as a biology student, I was certainly never taught them. Since biology is restricted to the study of life, then its axioms would, presumably, set out life’s universal conditions.

Aristotle, the founder of biology, was a specialist in first principles. He wrote the world’s first systematic treatise on logic, Organon, much of which still stands today as the basis for deductive logic. He fully understood the importance of axioms as points of stability and reference: that they are a backstop to the tendency for questioning to become diffuse, or circular, or to pass into an infinite regress.

Aristotle was also aware that we can view things from different perspectives and therefore describe and explain them in different ways. His four ’causes’ outlined major ways of providing a definition or explanation of something . . . by describing what it is made of (material cause), its major or defining features (formal cause), how it was made (efficient cause), and what it is for (final cause).

Aristotle noted that to continue existing (to perpetuate their kind) living beings must reproduce. He summarized this principle by saying that all living creatures ‘partake in the eternal and divine’. By this he meant that organisms can replicate their kind (species) indefinitely (eternally) provided they can survive to reproduce. Today, using different words, we might refer, like evolutionary biologist Richard Dawkins, to the ‘immortality of our genes’.

For Aristotle, the intellectual search for the foundation of biology, what it means to be a living being, ended appropriately with its final cause, with what it is ‘for’. And this, Aristotle considered, was ‘survival and reproduction’.

Biologists today think little of Aristotle, or axioms, or final causes, but any cursory examination of biological texts reveals that his general assumption about the foundations of biology persists, though rarely expressed as a necessary first principle. Even so, it remains a universal truism about life that cannot be expressed in simpler terms; it is the impetus or drive behind life when viewed from the perspective of unified and agential (directed) process.

We cannot expect logical certainty in biology, but the biological axiom is the nearest we get to a simple and easily comprehended necessary and sufficient condition for all biological existence. It observes that though organisms, as agents, differ greatly in kind, complexity, and means of attaining their goals, they share the biological axiom as an ultimate  ‘unity of purpose’.

The biological axiom expresses, as succinctly as possible, the universal agential goals that ground all living organisms – from the simplest organism at the dawn of life to the complex modern human.

Logical & biological necessity

The biological axiom is not a matter of philosophical or scientific speculation or contention – it is our most succinct way of expressing a basic assumption that underpins the study of biology – a point of departure for biological thinking. As Richard Dawkins expresses it: ‘We are survival machines‘.[4]

Aristotle noted that we do not ask ‘Why do organisms try to survive and reproduce?’ because we understand that to deny survival and reproduction is to cease to exist – and that does not make biological sense. Organisms that do not, or cannot, survive and reproduce die out – and in ceasing to exist they become biologically irrelevant.

In a world of perspectiveless facts there can be no logical grounds for value. Here we follow Aristotle in taking a biologically necessary normative perspective on ‘life’. . . that – ‘It is better to exist than not exist‘ and ‘it is better to live than not live’ (Aristotle, GAi23, 731 a24-b8; GAi4,717a21-22; GAii1,731 b20-21).

Today we could pass on to Aristotle some recently acquired additional information. Aristotle’s biographer, evolutionary biologist Armand Leroi, retorts to the question ‘Why do organisms need to survive and reproduce?‘ with ‘Because natural selection made them so‘.

Denying the biological axiom is logically possible, but it is biologically incoherent in the same way that our human desire for health and happiness is not logically necessary, but self-evident.

Principle 8 – the biological axiom is not a logical necessity, but it is a necessary condition of life – a biological necessity

The power of the biological axiom is that it expresses in a succinct way, underlying principles that have been elaborated and explored in diverse ways by the organic complexity spawned by natural selection.

The biological axiom is a foundational statement of biological fact, purpose (a reason or function), agency, and normativity.

As a statement of fact – it describes the way organisms are

As a statement of purpose – it explains what they are for 

As a declaration of agency – it tells us what they do

As statement of normativity – it tells us what they ‘prefer’ or value

But how can organisms possibly have values?

The Means

Expressed in human-talk . . . agents pursue their goals by adopting ‘strategies’ as a means to their ends. To put a strategy into effect requires whatever resources can be summoned up, both physical (internal and external) and psycho-behavioural. Human goals are not achieved with mind alone.

Most organisms are mindless but, just as they are ‘competent without comprehension‘ and ‘for without foresight’ so they are rife with mindless ‘strategies’, both short- and long-term.

Humans achieve their goals by using conscious reasoning as part of their strategy to satisfy their wants, wishes, and desires. Our human goals are decided by what we value at any given time, whether this be something small and individual, like the need to scratch, or something importantly collective, like the passing of legislation in parliament.

We humans do what we do because of both our conscious and unconscious (intuitive) values: it is values that are the drivers or motivators of our activity and behaviour. 

Physical resources

The business of survival, reproduction, and flourishing engages every structure in an organism’s body. These structures have evolved over the long term as functional adaptations to historical environments (EEAs, or, environments of evolutionary adaptation). Over the short term there are all kinds of behaviour to deal with current circumstance.

Human normativity

The word ‘normativity’ refers to the way we designate some actions or outcomes as good (desirable, permissible) and others as bad (undesirable, impermissible): it is an idea that is intimately connected to human morality and ethics.

Today’s prevailing view is that the moral discourse associated with normativity is, of necessity, confined to those organisms capable of conscious and rational choice, namely those that have ‘interests’ to promote or defend. The domain of normativity is therefore necessarily restricted to humans, although a concession is sometimes made for those sentient animals that can experience comfort and pain.

This anthropocentric view of normativity regards the idea of non-human organisms having values as ridiculous. The idea of an oak tree for example, having values, is surely absurd?

This anthropocentric view of values and morality is sometimes tempered by moral naturalism, the claim that human morality is grounded in biological facts. The thesis of moral naturalism developed on this web site embraces a moral realm that includes all living creatures by taking account of their graded complexity. This idea is explored more fully in the articles on human-talk, the metaphor fallacy, [20] and environmental ethics. These articles consider the possibility of extending the ethical domain to include the entire community of life.

Stated briefly, the predisposition of organisms to survive, reproduce, and flourish (the biological axiom) grounds all biological normativity, humans included, although it is clear that humans pursue the ultimate ends of the biological axiom through the proximate ends of happiness, wellbeing, and flourishing.

Anthropocentric ethics often indirectly insists on the primacy of conscious values by pointing out that we cannot derive values from states of the world (facts). We cannot derive an ‘ought’ from an ‘is’. There is no logical necessity for a transition from statements of fact to statements of value. Because I feel ill, there is no logical necessity to visit a doctor.

It has been argued above that life, by its very nature as expressed in the biological axiom, embodies value. There may be no logical necessity for values to flow from biological facts but organisms, of their very nature, have no choice: for an organism to exist without value is to deny life. Values flow from biological facts as a matter of biological necessity. And when our very existence is at stake, biological necessity trumps logical necessity.

If you accept the reasoning above, then you have accepted a substantive case for a generalized biological normativity. The significance of this is that once the biological axiom is accepted as a normative statement, then we have an answer to the question ‘What are organisms for?’ and much follows. We have also identified ‘goods‘ (values) that are within nature independently of human minds.

Living organisms would still strive to survive and reproduce (albeit unconsciously) in the absence of humans. And the ways (means) of achieving these goals are (unconsciously) valued (selectively filtered) to attain ends. This selective filtering (as a process that increases the probabilities of particular outcomes) is a capacity that arises within organisms and finds its extreme expression in the choices that express human values. Organisms (agents) exist (fact), and they exist to survive, reproduce, and flourish (fact, value, purpose).

But isn’t this a metaphorical reading of human values into a value-neutral nature? Isn’t it imputing human values to creatures that simply cannot express value? How can we possibly claim that an oak tree has values!

The claim being made here is not that a n oak tree has human values but that it has primordial value-like properties that are recognizably congruent with those of human beings.

The drive for life to survive and reproduce is so pervasive and strong in nature that trying to remove values and value-talk from biology is as difficult as trying to remove purpose-talk. We are not being intellectually slovenly when we treat organisms as ‘agents’ with ‘interests’, albeit unconscious ones. Whether they have corresponding ‘rights’ (and how these are to be assessed and administered), is another matter, discussed in the article on environmental ethics. All biological values are ultimately derived from the purposive drive of biological agents to survive, reproduce, and flourish – the biological maxim.

There are two major reasons why we ignore the values present in all organisms: the human arrogance of the metaphor fallacy and the fact (only appreciated since Darwin) that the community of life exists in graded organic complexity that is physically continuous and connected in time.

Biological normativity

We can give undue emphasis to our human conscious deliberation, not by overemphasizing our reason (although we can easily ignore both the role of shared biological intuition in driving our own reason, while totally ignoring the mindless reason manifest by other organisms) which is clearly a miraculous and distinctive faculty, but by underestimating the shared foundation of our values in our shared biology.

The biological axiom tells us, in a general sense, why all biological agents do what they do. It tells us how they ‘value’ the ultimate goals of survival and reproduction and the proximate goal of flourishing.

Biological normativity is the playing out of both unconscious (mindless) and conscious (mindful) goals in the face of circumstance. Though the underlying values (survival, reproduction, flourishing) are universal, they will ‘play out’ differently according to the biological agent. The physical structures and behaviours (‘strategies’) adopted by a spider to obtain its food and produce offspring are very different from those of a sea urchin or eucalyptus tree.

Humans, though they adhere to the biological axiom, are not consciously motivated by its (ultimate) precepts. We are not mentally preoccupied with perpetuating our genes or surviving from one moment to the next, instead we pursue the more immediate (proximate) goals of happiness, wellbeing, and flourishing.

Biological Normativity – Fact & value – Unbeknown to 18th century Scottish philosopher David Hume, it is now clear that there are universal natural values derived from the goals of the biological axiom. Values are not added to the world by humans, they are part of our universal biological nature. The worlds of fact and value are not irreconcilable, they are one. Organisms defying the biological axiom have been weeded out by the mindless rationality of natural selection. Behaving in such ways is, of course, both biologically and logically possible, both short- and long-term, but it is contrary to our biological nature and cannot persist. Reason is a uniquely human faculty that devises different ways (moralities, ethical systems, codes of behaviour, notions of the good) to accommodate the demands of the biological axiom.


The biological axiom is a statement of value in its most generalized form: not in the specialized sense of human intentional psychology – as ‘choice’ or ‘preference’ or even ‘intuition’ – but as the increased probability of a particular response in a particular circumstance. The way that all organismal agency constrains outcomes.

When we say ‘The eye is for seeing’ we are acknowledging that the existence of the eye is a consequence of a selection process. Once we thought the selector was God, today we are inclined to think it is nature itself – natural selection. Where there is selection, there is selection ‘for’.  And, in nature, where there is an aim, a ‘for’, there can be assistance or hindrance in attaining that ‘for’. This explains how biological agents can be mindless ‘beneficiaries’ of circumstance. An amoeba, a dandelion, and a human can all be thwarted in attaining the goals of the biological axiom. The nature of the thwarting depends on the particular agent and its complexity.

This is not a question of values and no values (values are real in all nature) Rather, it is a matter of graded values; values by degree.  This is also the natural and mindless normativity present in nature and independent of human minds.

In sum: clearly organisms do not value in the same way as humans value, but this does not mean that they do not value at all. The valuing exhibited by mindless organisms is not the unreal ‘as if’ valuing of metaphor but the graded valuing that has emerged out of the evolutionary process.

Because we humans share the ultimate values of all living organisms (the biological axiom) we intuitively identify with other creatures in a manner that is different from the way we relate to rocks. This is part of our accounting for human-talk and the anthropomorphic bias. It is why we can relate to the life of a bird, or even a plant, in a way that we cannot relate to a rock. We intuitively recognize our evolutionary connection to the community of life, its agency, and the biological normativity expressed in the biological axiom. There are many insights to be gained when we acknowledge the biological grounding states that makes real the language of human intentional psychology as it is applied to nature (see human-talk).

With increase in material complexity there is a corresponding increase in complexity of our conceptualization of the relationship of cause to effect. In the inanimate world this relationship expresses the impersonal ordering of matter by physical constants. In mindless nature there is the additional ordering of organic matter causes produce effects that are ‘for the better’. These are short-term and long-term behaviour, processes, and structures (adaptations) that promote the survival, reproduction, and flourishing of organisms. These are ordering effects that, in human-talk, are ‘beneficial’ to the organism. Humans then manifest self-correction by conscious deliberation.

There is a continuum across the natural world running from inorganic cause and effect to organic purpose, agency, and normativity.


Principle 9 – the so-called metaphor of human-talk (anthropomorphism) expresses not metaphor (an ‘as if’ figurative comparison not based in reality) but a difference more scientifically understood as based in degree of organic complexity (a similarity grounded in reality)

The entire community of life is sustained by plant primary productivity. This time-lapse of annual global vegetation growth draws attention to the agency of plants as they provide sustenance to the community of life in much the same way as the heart provides sustaining blood to our bodies.

This cartogram animation uses satellite observations from NASA’s Moderate Resolution Imaging Spectroradiometer (MOD17) that is able to detect the cumulative composite Gross Primary Production (GPP) of the biosphere on land. This productivity is nature’s ‘fuel for life‘ as it gives us an idea of how the biosphere is utilising the sun’s energy to support its organisms, turning plants into the biomass factories that support life higher up the foodchain.
When and where nature ecosystems are most productive depends a lot on the time of the year. The animation of productivity shows how the changing seasons determine the variability of energy production throughout the year. Distribution of landmasses lead to the tropics being over-proportionally present in this image, especially in the northern hemisphere’s winter.

Courtesy WorldMapper – Accessed 27 September 2021

Life is . . .

. . . not being dead
. . . greater than the sum of its parts
. . . complex chemical organization
. . . different things to different people
. . . a mystery
. . . a journey
. . . don’t know
. . . a mission to help other sufferers
. . . what you make it
. . . life begins after death

Kristine Kerr, Gourock, Renfrewshire

To which it may be added that death is no mystery because:

. . . life after death is the same as life before birth


In seeking to answer the question ‘What is life?’, we must consider why agency be given precedence over the plethora of other universal characteristics of life available from today’s many academic systems of biological representation.

Science attempts to describe the world in a detached way that minimizes the impact of human subjectivity. The view expressed on this web site is that science does not get closer to ‘reality’ by drilling ever deeper into the physical constituents of matter. Instead, we understand and explain the world using multiple systems of representation (disciplines, frames of reference, points of view) all of which are equally valid. This does not relativize knowledge as each system has its own measures of effectiveness that are constantly reassessed. However, it does mean that the particular system we emphasize depends on our special interests and the goals we currently pursue – which is a pragmatic choice.

This is why it is so difficult to define life. A fair approach would treat all representational systems equally – which is much too cumbersome to attempt.

There is a solution. The objects we perceive, the criteria and cognitive faculties we use to discriminate between them, the sense of time in which they are experienced, the scales and perspectives from which we view these objects . . . all are influenced by our humanity (our human cognition). This does not make the world a subjective illusion, but it does make it our best human interpretation.

We can therefore acknowledge our humanity and deliberately adopt a human perspective on ‘life’, a common-sense manifest image perspective that is readily understood and therefore meaningful, while at the same time acknowledging the more detached and scientific vision expressed through multiple systems of representation (the principles, terminologies and practices of diverse academic disciplines).

When viewed through this human lens, as Aristotle appreciated, it is ‘agency’ that we most strongly associate with the living – what biologist Richard Dawkins has called ‘functional complexity’ – and it is agency driven by the conditions of the biological axiom.

Why agency?

Whatever our biological enquiry, it is ultimately to the whole functioning organism that our attention is drawn: this is a presupposition on which biological enquiry proceeds. We intuitively recognize the integrated agential autonomy (unity of purpose) of discrete organisms as a form of concentrated individuality that is not found in the inanimate world, or even in biological entities such as genes, tissues, populations, or cells.

Scientists are no longer encumbered by Aristotle and his causes, but the topic of agency begs that we revisit teleology as a mode of scientific explanation outlined in his Physica Book 2. Here he outlines the general character of the explanations we give to scientific questions and considers their relevance to biological explanations in particular.

He outlines four general modes of explanation (which he calls ’causes’, although a more appropriate word for us would be ‘because’): we describe constituents (what something is made of – his material cause); we note defining or essential features (shape, arrangement, structure, appearance etc. – his formal cause); we say how they originated (how they arose, emerged, or were produced – his efficient cause); and we observe what they are for (their aim or end – his final cause)? Of these four ‘causes’ (as he called them) it was the final cause that, Aristotle believed, completed explanation. Formal and final causes were abandoned during the Scientific Revolution for their unscientific implications and philosophical obscurity.

A modern example of the application of Aristotle’s four causes might be the way that biologists have argued about the best way to define the gene: should it be structural (material cause), positional (formal), historical (efficient), or functional (final)?

Aristotle’s four ‘becauses’ are deceptively inclusive. They are both static and dynamic while incorporating both structure and function. By considering potentiality, actuality, and the temporal sequence of efficient cause, they allow for history and development, past and present, while final cause embraces all these factors within the notions of purpose and agency. They describe the way things are now, but also account for change (Aristotle’s primary objective) by explaining how they came to be. And their meaning allows some flexibility of interpretation (Aristotle pointed out that the Greek word aition as ’cause’ had various senses).

The four causes divide neatly into two pairs. The material and efficient causes capture an analytic ‘bottom-up’ physical and material perspective on the world and change. Formal and final causes offer a synthetic ‘top-down’, integrating, unifying, agential, and purposive perspective. Scientists of the Scientific Revolution (mostly astronomer-physicist-mathematicians) abandoned Aristotle’s formal and final causes as too abstract, if not altogether mistaken, bequeathing us a mechanistic world of matter in motion.  In this way non-human living organisms were united with the material and efficient. By restricting purpose and agency to humans, and without the benefit of the theory of evolution, this was a distancing of humans from their continuity with the community of life, a distancing that persists today.

Aristotle’s biographer Armand Leroi, an evolutionary biologist working at Imperial College, London, presents Aristotle’s causes in a schema that represents today’s biology in a very general way by equating material cause to biochemistry and physiology, formal cause to genetics, efficient cause to developmental biology and neurophysiology, and final cause to evolutionary biology and the study of function and adaptation. Leroi concludes that Aristotle totally transformed the transcendental world of Plato ‘ . . . by the time he was done, matter, form, purpose and change were no longer the playthings of speculative philosophy but a research program’.[31]

Aristotle wanted to know, not just about order in general, the project of science in its entirety, but what was unique about the particular kind of order, change, and coming to be, that we see in biology.

‘It is not good enough to study the stars no matter how perfect they may be. Rather we must also study the humblest creatures even if they seem repugnant to us. And that is because all animals have something of the good, something of the divine, something of the beautiful’ . . . ‘inherent in each of them there is something natural and marvelous. Nothing is accidental in the works of nature: everything is, absolutely, for the sake of something else. The purpose for which each has come together, or come into being, deserves its place among what is natural and good’ . . . ‘The nature that crafted them likewise provides extraordinary pleasures to those who are able to know their causes and are by nature philosophers.’  

Aristotle – De Partibus Animalium (The Parts of Animals) 645a15


Aristotle’s sentiments are aptly referred to as ‘The Invitation to Biology’.

Aristotle’s central idea – the cement that binds all biology together – revolves around his final cause: it is this that gives life its ‘unity of purpose’. Only now, after over 400 years of rejection, this idea is gradually being restored to scientific respectability through a recognition of the limitations of a micro- perspective on life, and the resurgence of a philosophical position reinstating purpose in biology (outlined in the article bioteleological realism). This is a recognition that: purpose in nature is real – organisms can be ‘for’ without foresight. Purpose was naturalized by Darwin who demonstrated that final cause does not require future causation. Even as formal explanations. final causes do not imply the empirically impossible.

Smallism has now run its course as we have come to realize that biology comprises much more than just physical forces, molecules and fundamental particles, and energy flows. We also need to know the role of life (entire living organisms) in the broader contexts of surrounding systems . . . environments, ecosystems, and the biosphere in its entirety.

An organism is as real as a molecule. We need a synthetic or holistic overview as well as an analytic and reductionist one. And, for convenience, we need an explanation that is neither anthropocentric nor anthropomorphic but, nevertheless, human friendly.


Aristotle also noted that teleology has two parts, the ‘of which’, aim, or function (say, of an eye ‘to see‘, of a heart ‘to pump blood‘) and the ‘for which’ or beneficiary, the organism deriving the benefit.

Mysteries, rightfully resisted by the Scientific Revolution, have now been resolved in naturalistic ways. The genetic code acts as life’s ‘inner nature’ or, to use Aristotle’s analogy, the ‘inner craftsman’ that provides the critical information whereby ‘like begets like’. Even Darwin was unaware of this genetic foundation. We recognize ‘like’ organisms by their intergenerational similarity as the formal cause that gives them structure and meaning.

From the Scientific Revolution to the time of Darwin and beyond, teleology was regarded as an Aristotelian solecism. How can nature display purpose when purpose is something that only exists in human minds? But teleological language (human talk) would not go away and a philosophical industry was built around its clarification. Perhaps purpose-talk could be avoided altogether by ignoring what things are ‘for’ and, instead, simply stating what they ‘do’?

It is argued here and elsewhere on this site that purpose in nature is real, and it is not our purpose. We have failed to understand how deeply our resistance to this idea has become ingrained in our collective psyche and how liberating its negation will be.

Final causes explain the presence of features, but exert no “mysterious pull” from the future. They rather function quite literally as the direction-givers and the ends and limits of developments necessitated by formal-efficient or material-efficient causation. In this way, they provide both the first component of a teleological explanation and the heuristic starting point for investigations that will lead to a statement of the complete teleological explanation of the phenomenon in question. This does not mean, however, that final causes have only a heuristic value: since in demonstrations of the teleological type the final causes are part of the conclusion that is being demonstrated, the practice of Aristotle’s natural science demonstrates the very existence of natural teleology.

Mariska Leunissen. 2015.

Explanation & teleology in Aristotle’s science of nature. Cambridge University Press

The single most forceful argument against teleology is that nature cannot operate with foresight as the language of purpose implies.  Leunissen (above) is showing that this apparent foresight is explanatory primacy, not causal primacy.[21]

Humans view and interpret nature from a human perspective and human scale. Science tries to overcome this cognitive bias by increasing the perspectives from which we view ‘life’, most notably by using technology to narrow down and widen out.

Organisms are meaningful units regardless of scale and this human bias

Agency (purpose) is both real in nature, and an explanatory lens that is close to our human interest because it draws together in a simple and engaging way what it is that we humans recognize in ‘life’ as distinct from  ‘matter’: it makes intelligible phenomena that would otherwise be dissociated facts of our universe‘.[18]

Unfortunately, the analysis of his central  biological claim – that biological explanation must revolve around ‘ends’ (his final causes)  is now buried in decades of abstruse and mostly unsympathetic philosophical debate. His simple thesis was that biology, at its core, is a process of reverse engineering . . .  finding out what organisms, their parts, and their behaviour, are for.

.  for Aristotle, the theory of
natural teleology is not an a priori assumption, but a scientific hypothesis that he uses to make as much sense of the natural world around him as he possibly can and thereby to locate the good and show that
“there are gods here too.”

In Aristotelian terms, humanity had at last located the ‘inner craftsman’ that had been scorned by the Scientific Revolution. This was an answer to Aristotle’s superficially simple and silly (but crucial) question ‘Why do neither snakes nor stars have feet‘?[17]

The question remains. From what perspective are we to take a summary view of life?

We humans have cognitive limitations, and it seems we have reached an impasse. Science has extended our biological knowledge beyond anything Aristotle could have dreamed. We have plumbed life’s structure, function, microscopic material composition, behaviour, dynamic process, energy flows, the communication of information, genetic properties, genomics, informatics, proteomics . . . physics, biochemistry, ecology . . . ? The academic arena is now so vast that it seems impossible to explain life briefly and coherently from this multitude of aspects all at once; yet to omit one is do it a disservice.  The place of whole organisms within their wider environments, including the greater whole – as communities, populations, ecosystems etc. – is as important as the circumscription of their smallest components. Is there a priority of scale when we break down organisms into organs, tissues, cells, and macro-molecules?  We cannot explain an ecosystem in terms of the molecules that make it up, even if this is theoretically possible.

This is where we are at now. If we want to define life, then we must define it as viewed from many aspects. We try to overcome our human ‘subjectivity’, our human focus, by using technology that extends our biologically given senses into unfamiliar worlds, and that is how science has advanced.

But Aristotle gave us an option. If we view must view the world from a human perspective, then perhaps we can use that perspective to its greatest advantage. Central to our humanity is our purposiveness, agency, and intentionality.

In (over)simplified terms: scientists of the early modern period provided scientific explanations that were restricted, in Aristotelian terms, to material and efficient cause i.e. what something is made of (its material composition), and the trigger for it doing whatever it does (today’s understanding of ’cause’). This approach to scientific explanation gave rise to what is characterized in the history of science as a mechanistic world of matter in motion and this conception replaced Aristotle’s world view of a cosmos filled with life-like agency. Only with Darwin was a more organic perception of the world reinstated although the old preoccupation with the physicochemical as somehow prior has persisted.

Aristotle’s third and fourth explanatory (be)causes, which he believed were necessary for a complete scientific explanation, were his formal and final causes. These were considered problematic and therefore best discarded or ignored. Final cause (‘that for the sake of which’ or ‘for’) was problematic in several ways: it implied future causation along with the possibility of supernatural influence and the intrusion of anthropomorphism. Formal cause as ‘that which makes it what it is’ was also an ambiguous, abstract and spooky business, suggesting mysterious philosophical essences or some-such.

Aristotle argued that efficient cause without final cause was like a fire that spreads uncontrollably in all directions, while final cause is an outcome to an ordered (not random or accidental) and efficient process (De Anima II.4,416a15-18). He was also adamant that purpose arose in nature itself; it was not placed there by either God or the human imagination.

It is significant that Aristotle’s four causes divide neatly into two pairs. The material and efficient causes capture an analytic ‘bottom-up’ physical and material perspective on the world and change. Formal and final causes offer a ‘top-down’ synthetic, integrating, unifying, forward-looking, agential, and purposeful perspective on the universe. Aristotle’s telos implied the mesmerizing thought that, at its very simplest, every cause has an effect as a primordial ‘purpose’, however obscure or tiny that might be.

The influence of the Scientific Revolution on contemporary science can be exaggerated, but by emphasizing a mechanistic world of matter in motion, and abandoning Aristotle’s formal and final cause, ‘life’ and ‘agency’ were squeezed out of the scientific world, thus uniting non-human life with the material and efficient, essentially the inorganic. Humans were the only creatures with ‘real’ agency. By restricting purpose and agency to humans, and without the theory of evolution, a gulf was opened up between humanity and the rest of life – a gulf that is yet to be satisfactorily bridged.

The Scientific Revolution’s rejection of Aristotle’s formal and final causes was, in part, an attempt to remove the problematic ideas of purpose and agency from biology. These notions introduced a mysterious (?supernatural) life-force and obscure philosophical ideas that were not amenable to empirical investigation. Exorcising life-forces from non-human organisms was considered a scientific service. ( them greater resemblance to the inanimate world than the animate and conscious world of humans). But agency and purpose have remained a part of the language and academic culture of biology.

After 2500 years we are now inadvertently returning to Aristotle’s way of thinking by including formal and final causes in our consideration. True to the Scientific Revolution we acknowledge the importance of describing what something is ‘made of’ (its material cause), and ‘how it arose or was made’ (efficient cause). But we are only just beginning to acknowledge, philosophically, that much of our biology is reverse-engineering – not just the investigation of what living systems and structures ‘do’, but what they are ‘for’ – both individually, and collectively through the unity of purpose expressed in the biological axiom (final cause).

In the absence of this unified agential explanation of life, biology becomes a collection of dissociated facts of the kind we use to describe the inanimate world. It is the purposiveness of biological agency that gives life its meaning through the ultimate goals of survival and reproduction and the proximate goal of flourishing, all as a matter of biological necessity.


A satisfying scientific answer to the question ‘What is life?’ must be a full one. It must involve much more than a response detailing ‘what it is made of’ (material cause) and an assumption that something that is small is more ‘real’ than something that is big. Life is more than subatomic particles, energy, or information: it is even more than the genetic code. Also, what an organism is ‘for’ brings with it a meaning that extends well beyond what it ‘does’. Life is matter, yes, but matter with additional non-metaphysical (real) coordinated – call it what you will – zing, oomph, drive, direction, motivation, dynamism, purpose . . . or telos.

A full explanation of a chair, we believe, must include a description of what it is ‘for’, its final cause or purpose. Sadly, for many scientists and philosophers, even today, organisms are no more ‘for’ anything than are planets or rocks. A chair has more purpose than an organism.

As complexity increased after the Big Bang, so life emerged as matter with distinctly novel properties and relations. To provide a full and satisfying explanation of what it is to be a living organism we need more than material and efficient cause.

It is argued in this article here, and that on human-talk (see metaphor fallacy) that our science would better reflect the world if it treated the categories of human-talk as existing in reality by degree, rather than as unreal metaphor.

Today, long after Darwin naturalized teleology by clearly demonstrating that the words ‘for’ and ‘in order to’ do not necessitate the foresight we associate with human intention, we still balk at these words. We have gone to extraordinary lengths to avoid the word ‘purpose’ in its extended sense, preferring the expressions ‘adaptive significance’ and ‘function’ (euphemisms for what would have been far better treated as mindless purpose) which are a form of circumlocution introduced to overcome the presumed metaphorical character of human-talk.


‘No matter what your race, religion, or gender; when you first step outside your door in the morning and feel the fresh air in your lungs and the morning sun on your face, you close your eyes and smile. In that moment you are feeling life as it should be. No defining, no understanding, no thinking. Just that feeling of pure bliss. For that is what human life is.’

Courtney Walsh, Farnborough, Hampshire

Key points

Note: human-talk is indicated using quotes.

  • Darwin dramatically changed our understanding of organisms as they exist in space and time. He changed them from discrete kinds uniquely created in a single moment, to a community of life that is physically connected across time through the process of graduated organic emergence, divergence, and complexification that is descent from a common ancestor
  • Darwin’s On the origin . . . contained two profound insights that have not yet found their way into either biological science or the public imagination. First, he naturalized teleology by demonstrating that, in spite of the metaphorical language frequently applied to nature, goal-directedness (purpose) arises in a natural way, without the need to invoke either the supernatural, or the foresight of human intention. That is, he showed how purpose in nature is real. Second, he demonstrated the close physical connection that exists between the entire community of life through descent from a common ancestor and therefore, incidentally, that life concepts and processes show resemblance that is grounded in reality, in nature itself, not in metaphor.
  • Biological agency is manifest through three key elements which, expressed in human-talk, are the agent, its mission, and its means. The mission equates to purposes, goals, or interests, while the means entail strategies that are not mere mental ‘intentions’, but physical activities.
  • Organisms are agents that pursue biological interests through the ultimate (long term, multi-generational adaptations) as goals of survival and reproduction as expressed in the biological axiom, and the (short term, single generation phenotypic traits). Goals arise out of the very nature of living matter. In their advanced human form, ancestral goals arise out of their biological evolutionary foundation as the ‘will’, ‘passions’, ‘intuitions’, or ‘appetite’.
  • The grounding principles of biological agency are universal though biological agents and their strategies vary in degrees of physical and behavioural complexity
  • We acknowledge life through the agency of living organisms with a predisposition to survive, reproduce, and flourish, this being biologically necessary ultimate conditions for their existence (the biological axiom).
  • humans pursue the ultimate ends of biological axiom I through the proximate ends of happiness and wellbeing
  • We apply a normative idiom to organisms and their traits because organisms, in accordance with the biological axiom, can be beneficiaries of circumstance
  • The biological axiom is a statement of both fact and value since it provides the basis for biological activity: it is the grounding for all normativity, including human values.
  • Biological agency is expressed in terms of semi-autonomous structural, functional, and behavioural flexibility – the capacity to act and react, to adapt, both short- and long-term. Biological agents exhibit a unified short-term independence by regulating both inner processes, and the interaction with surroundings. Over the long-term self-replication with heritable variation and differential reproduction facilitates adaptation and evolution.
  • Living organisms differ from inanimate matter in their autonomy expressed through the capacity to replicate (recreate) themselves and to constrain the circumstances of their existence in a way that promotes their survival, reproduction, and flourishing
  • Evolution is a process of selection (natural selection). Where there is selection, there is selection ‘for’. And, in nature, where there is an aim, a telos, or ‘for’, together with a beneficiary (under the value conditions of the biological axiom) then there is purpose, agency and a foundation for normativity that distinguishes the living from the non-living, and is independent of human cognition.
  • Today the notion of agency no longer brings with it the implication of mysterious supernatural forces or complex abstractions – it has been thoroughly naturalized. But a few philosophical difficulties remain. Among these is the conflation of nature with human experience, generally regarded as an extension of the old personification of nature and an anthropomorphic cognitive bias. Part of this is the use of anthropomorphic language (human-talk) to bridge the gap between human characteristics and their analogues or evolutionary antecedents as they exist in non-human organisms.
  • Biology has inherited two fallacies from the thinkers of the Scientific Revolution: the metaphor fallacy as the claim that all anthropomorphism is metaphor; and the purpose fallacy as a claim that the word ‘purpose’ can only be used meaningfully in the context of mindfulness


Adaptation – the evolution of traits with functions that enhance fitness
Agency (biological) – unity of purpose, goal-directedness. Comprising agents (organisms) their goals or purposes (ultimate goals (biological axiom) of survival and reproduction, proximate goal of flourishing) and their means (including the mindless use of physical and behavioural resources needed to pursue goals, as well as conscious strategies)
Agent – something that acts or brings things about. Mindless inorganic agents include objects like missiles, cities, and computers. In biology – typically an organism (sometimes extended to include genes, groups, or other entities, even natural selection itself) as a (semi)autonomous individual with inputs as flows of energy, materials, and information, internal processing, and outputs as energy, waste, action and reaction in relation to surroundings. An organism directed by real goals (these may be mindless, that is, without conscious intention)
Agential realism – the claim that non-human organisms exhibit agency in a mindless way, and that humans combine both mindless and minded agency: the grounding of cognitive biological metaphors in non-cognitive biological facts
Anthropocentric – to view and interpret circumstances in terms of human experience and values
Anthropomorphism – the attribution of human traits, emotions, or intentions to non-human entities
Apomorphy – a specialized trait or character that is unique to a group or species: a character state (such as the presence of feathers) that is not present in an ancestral form
Autopoiesis – self-replication combined with self-maintenance and modification is sometimes referred to as autopoiesis
Bioteleological realismthe claim that purposes exist in nature and that most cognitive metaphors used in science are grounded in non-cognitive biological facts
Behavioural ecology – the study of the evolution of animal behavior in response to environmental pressures
Cognitive ethology – the study of the influence of conscious awareness and intention on the behaviour of an animal
Cognitive metaphor – a metaphor used in the context of human intentional psychology
Evolutionary biology – the study of evolutionary processes (notably natural selection, common descent, speciation) that created the community of life
Fitness – a measure of reproductive success (survival) in relation to both the genotype and phenotype in a given environment
Genotype – the genetic constitution of an individual organism, encoded in the nucleus of every cell
Human-talk – the application to non-human organisms of language usually restricted to humans and human intentional psychology
Metaphor – figurative language as ‘nonliteral comparisons in which a word or phrase from one domain of experience is applied to another domain’. An ‘as if’ direct (not a ‘like’) comparison that is not grounded in reality e.g. ‘You are a rat’.
Normative realism – the view that normativity has its origin in biology through the mindless and mindful ultimate goals of survival and reproduction, and proximate goal of flourishing
Personification – the representation of something in the form of a person
Phenotype – the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment
Physical reductionism – the view that biological phenomena can be adequately explained in terms of physico-chemical entities
Purpose – Aristotle’s final cause or telos; the reason why anything is done, or made, or for which it exists; an end, aim, or intention; what something is ‘for’
Proximate explanation – an explanation dealing with immediate circumstances
Synapomorphy – a characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants
Trait – a unit of the phenotype (physical or behavioural)
Ultimate explanation – a long-term explanation (e.g. in biology as a measure of the fitness of a particular trait)

Media Gallery

What is Life? – with Paul Nurse

The Royal Institute – 2019 – 59:51

Rethinking Thinking: How Intelligent Are Other Animals?

World Science Festival – 2020 – 1:33:46

First published on the internet – 13 Sept 2021



X-Ray image of stingray
Courtesy loctrizzle – – Accessed 25 May 2017

Tesla MRI of the ex vivo human brain at 100 micron resolution (100 micron MRI acquired FA25 sagittal) (downsized, original speed).gif
Courtesy Wikimedia Commons – Accessed 20 September 2021

X-Ray of stingray
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