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This article is an examination of science itself – what it is, how it is done, and what distinguishes it from other forms of knowledge. For a brief account of established scientific knowledge see Grand narrative of science. For an account of the emergence of modern science from philosophy during the Scientific Revolution of the early modern period see natural philosophy, and for a discussion of science and morality see Morality & sustainability

Science & reason


Science is magic that works

Kurt Vonnegut[8]


Science is the most rigorous possible refining of the categories we use to describe the order of the universe.



Submitting all of one’s beliefs to the trials of reason and evidence is an unnatural skill, like literacy and numeracy, and must be instilled and cultivated

Steven Pinker, Rationality (2021), p. 301

The Scientific Universe
Diagram demonstrating key characteristics of science.

. it uses technology to extend our biological senses
. it systematically organizes knowledge into frames or categories of explanation and understanding
. it operates within circumscribed scales or frames of reference
. it refines the categories (terminology, concepts) we use to explain the natural world
. it builds on previous knowledge – thus advancing and making progress
. it ranks different scientific disciplines according to the size-scales, inclusivity or complexity of their subject matter (similar to the nested Linnaean hierarchical classification)

Diagram Courtesy Wikimedia Commons

Today we regard science, and its application through technology, as one of the greatest achievements of civilization. For all its shortcomings and limitations it is a compelling answer to the search for secure knowledge and a grasp on reality. Scientific explanations of the natural world have achieved a degree of sophistication that could hardly have been imagined only a few centuries ago, revealing the wonders of the workings of the universe: how and when it began and how it will end, the interplay of space and time, the elementary particle constituents out of which the universe is made, the way the entire community of life on earth arose by modifications of a common ancestor, and how instructions encoded in molecules contained in each cell of our bodies influence the way that we look, feel, and behave.

Most scientists, though not experts in topics outside their own specialization, have confidence in the findings of their colleagues. As a botanist I have little knowledge of the complex way that climate change works but I accept the conclusion of climate scientists that human emissions, since the Industrial Revolution, are a major contributing factor to climate change.

But why should I favour the claims of scientists over those of commentators, politicians, pundits, and public intellectuals?

Science has proved itself to be our most reliable means of acquiring secure knowledge so this article examines the source of this success. ‘What is science, what makes it special and unique . . .  and how does it differ from other forms of knowledge?‘ It then examines ways in which our human nature (our human perception and cognition) constrain our reason and therefore influence our scientific world view.


The major branches of science developed out of the practical concerns of daily living: mathematics out the problems of engineering, building construction, surveying, and military arts; biology out of medicine and animal husbandry; chemistry out of metallurgy and dyeing; economics out of the management of trade and resources in both business and the home.

Though close observation of the world around us has always had practical benefit, for most of human history this kind of knowledge was regarded as being of minor significance in the face of the spiritual and religious forces that governed all aspects of peoples’ lives. Only in the modern era, and gathering momentum from about 1500 in a period referred to as the Scientific Revolution, has science been regarded as a worthwhile human endeavour.

However, by the 18thcentury Enlightenment the benefits of empirical studies were clearly apparent through its technological applications and the insights it provided to the workings of the natural world.

The religious world view came under increasing challenge as it became apparent that a literal interpretation of the Bible as an historical narrative was simply untenable. Biblical accounts were treated as metaphor and parable. Natural theology – the belief that science was uncovering the natural order of the universe placed there by an intelligent God at his Creation – made science more palatable. Science and reason were the clarion call of the Enlightenment which thirsted for new knowledge. Though still restricted to an elite (the educated) science was not the same as the priest-mediated processes of daily life – it could, in principle, be pursued by anyone.

The better our understanding of the operation of the physical world the more effectively it could be manipulated to advantage. Technology, especially that of the European Industrial Revolution, was a source of power that changed not only individual lives but that of nations whose armoury, ships and other technologies could be used to dominate others. The critical scientific mode of thinking inherited from the ancient Greeks was certainly a factor in the rise of European empires as they began to dominate the world during the Great Divergence.

What is science?

So what is that scientists and philosophers think science can do that other subjects cannot? Does science use some unique way of reasoning or employ some special procedure, techniques, or method? What is the magic scientific key that has allowed us to unlock the secrets of the cosmos, atom, and gene?

We can define science through its major subject areas – like physics, chemistry and biology – or describe it in very broad terms as, say, ”’the application of reason to evidence”’, ‘the attempt to understand, explain and predict the operations of the world’, or ‘the progressive rational refinement of mental categories’ – or we can note that science is a particular domain of knowledge. But none of these explains what it is that makes science special. After all, we are not looking for a list of scientific activities and, besides, subjects like religion, history and astrology also claim to explain and predict the world in a rational manner . . . but we do not think of these as science.

To define science in a convincing way we need to isolate those factors that make science unique, and if we find them, to say why they have been so effective. Why is scientific evidence regarded as more reliable than many other kinds of evidence – why is it that science works so well?

Philosophers now devote a complete discipline to the philosophy of science especially as it relates to the interaction of what scientists assume to be ‘real’ in the world (metaphysics) and how these claims relate to justifications, beliefs, and truth (the theory of knowledge or epistemology).[15]


Our understanding of the world can be clouded by all kinds of unjustified beliefs, dogmas, traditions, authoritarian doctrines, intuitions, and illusions. Objectivity attempts to maximize impartiality by making an honest attempt to put all possible biases aside.

In speaking about objectivity it is useful to distinguish between epistemic objectivity as claims about knowledge (for example, we know that water boils at 100 Co) and ontological objectivity as a claim about what exists (e.g. water or purpose in nature). Science, as factual knowledge, is objective while claims about existence are subjective.


Part of the attempt to be objective is to recognize that science can only be effective when dealing with questions that can, in principle, yield answers. By the time of the Enlightenment it was generally acknowledged that assertions about Gods, spirits, communicating with the dead and such were not amenable to testing. Science could not prove or disprove the existence of God: religious belief was a matter of faith, not scientific evidence. Scientific knowledge was therefore confined almost exclusively to tested assertions about the material world and this gave science a cachet of credibility and reliability.


Being objective means accumulating evidence that has been tested thoroughly using experiments, observations, and measurements based on extensive sampling. During the early Renaissance influential English philosopher Francis Bacon (1561-1626) described this approach as the logic of inductive generalisation based on observation and experiment yielding conclusions that appeared certain beyond all reasonable doubt, very like the conclusions of mathematics. This kind of evidence had a high predictive value . . . very different from the evidence of pseudosciences like astrology and clairvoyance. The assembling of evidence based on the experience of our senses, with experiment and observation, became known as empiricism.

Empirical generalizations

Another aspect of science was its way of representing the order of the universe using laws, principles, rules, and axioms based on empirical evidence. It is these empirical generalizations that describe the uniformities or regularities of nature based on repeated observations. These regularities vary from those that appear to be universal like the ‘laws’ of physics (called ‘laws’ for their likeness to exceptionless human laws) to those that are more probabilistic in character. It is the deciphering of patterns and constants in nature that gives us one of sciences greatest gifts – its capacity for prediction and retrodiction and therefore the potential for sound empirically-based environmental management.


We refer to well-researched and reliable evidence-based knowledge as a ‘fact’. So factual statements are statements based on strongly corroborated evidence to be contrasted with uncritical assertions or opinions.

As scientists we tend to speak of actual phenomena in nature as being factual (ontologically objective) forgetting that scientific facts are statements about our beliefs – part of the way we picture the world – part of a logical argument or theory. The phenomena themselves cannot enter logical relations or be more or less substantiated.[3] Of course the scope and reliability of scientific and other facts can vary – so that the facts of social science may be considered of a different order from the facts that we call the laws of physics. Nevertheless, factual knowledge is power. But this does lead us to ask a question like ‘Is this theory or piece of evidence true?’


We use the word ‘truth’ in a casual sense to imply something that is reliable or sure – but the word is often imbued with far more meaning than that.

The description of science as ‘The search for truth‘ has a Platonic ring about it . . . a sense that science is progressively unveiling an unchanging reality, an objective, absolute, and eternal state of affairs – the ‘truth’. This understanding is supported by the character of mathematics and universal physical laws.

In contrast, there are Kant-like approaches whereby we cannot know how the world actually is (noumena) because we cannot assume a privileged, detached, and God-like view of the universe – all we can ever know is the way it appears to us (as phenomena). This does not mean that the world outside our minds is imaginary or some subjective fiction – but it does suggest that it is our interpretation of a world that we can never know as it ‘really is’ – to ask how the world ‘really is’ implies that it can be viewed from a perspectiveless vantage point, which does not make sense. On this view science then becomes our best attempt at using reason to remove as much humanity as possible from scientific conclusions.

‘Truth’ is, of course, a slippery concept that has always been the subject of many theories. Here are a few:

In many cases we would accept that truth is ‘what squares with the facts’ although there is an element of circularity here since, insofar as science is the pursuit of truth through the establishment of facts, then truth boils down to the best that science can offer (correspondence theory of truth). This is a popular and common sense view. Then there is the relation between scientific language as a representation of reality – the idea of language as a metaphorical copy of reality poses many questions. There are many other perspectives on truth . . . that it is (expressed loosely) ‘what works’ (pragmatic theory), ‘what fits best with all our other beliefs’ (coherence theory), ‘what everybody agrees on’ (consensus theory), or ‘a social construct depending largely on those controlling the systems of communication’ (constructivist theory).

As we have seen, if we regard truth as ‘what corresponds to reality’ then we have the impossible task of stepping outside our system of beliefs to compare these with reality itself.

There are further possibilities: truth could be a primitive concept that cannot be meaningfully described in, or reduced to, other terms . . . Or perhaps it is a concept that serves no useful purpose, it does not stand for anything, it is ‘transparent’. That is, to describe something as ‘true’ is to say no more than that it is so (redundancy theory, deflationary theory), or that you approve of it (performative theory). Even if you are a redundancy theorist you may still maintain that the idea of truth serves an important role in communication (Australian philosopher Huw Price). The deflationary or redundancy theory (Frege, Ramsay, Blackburn) seems to be more in tune with current thinking. Certainly philosophical theories of truth have become less orientated towards the absolute while relativistic theories have lost favour.

There are complicated associations between ‘truth’ and ‘reality’. Scientists should be aware of the philosophical chasm confronted by statements like ‘I am testing my theories against reality’.

Whatever your opinion on ‘truth’ you will find it helpful to distinguish between:

a. the kinds of things that can be true
b. what makes these things true
c. the extent to which truth is in the mind, or in the world (or both)

While acknowledging the power of scientific explanation, we tend nowadays to take a more earthly view of what science can achieve. Since the word ‘truth’ carries all kinds of intuitive and philosophical baggage, debating the ‘truth’ of scientific statements can be decidedly unproductive.[17] Old notions of absolute truth in science seem to have gone especially as a keystone assumption of science is that it is defeasible, meaning it is always open to refutation and refinement.

Let’s just say that in science we apply the word ‘true’ to statements of justified scientific belief, noting that beliefs can be true without being justified and, of course, that what counts as justification may be controversial.

This might appear a watered-down version of truth so, for example, pessimistic induction points out that a large proportion of the scientific theories of the past have proved mistaken or inadequate, suggesting that scientific knowledge is an overrated and transient affair. However, this claim ignores the fact that new scientific theories do not totally obliterate the past but build on it by refining their predictive and explanatory power. Even so, most scientists have abandoned the Platonic idea of absolute scientific truth, accepting some form of fallibilism, the acknowledgement that in spite of their power, scientific claims are subject to endless revision and refinement.

Now that we have covered some of the major terminology applied to scientific thinking how far have we come? Have we discovered science’s magic ingredient? Here is an attempt to summarize the discussion do far:

Principle 1 – Science uses objective empirical evidence to produce facts as justified beliefs about the natural world. These facts are then assembled into empirical generalizations about the world that can improve our ability to predict future events.

Though much is condensed into this brief conclusion we have not unearthed the magic that makes science a special and unique form of knowledge.

Perhaps, then, it is the particular kind of logic we use to develop scientific explanations that has allowed us to penetrate the universe?

Scientific explanation: the Scientific Method

Aristotle noticed the way that explanations rarely exhaust the possibility for further questions: logically they require further justification. We justify knowledge by recourse to other knowledge and this continues in an infinite regress of explanation (or sometimes circular argument). So, for example, ‘Why did the chicken cross the road?’ ‘To get to the other side’. ‘Why did it want to get to the other side?’ etc. etc. Even serious scientific explanations can fall into this explanatory black hole of reduction. So how has this problem been addressed?


Aristotle‘s way of overcoming this regress was to begin with secure generalities. He thought that any secure system of knowledge needs a foundational underpinning of axioms (like Euclidian geometry), a bedrock of self-evident truths, first principles, essences, or certainties. Only then can you move to particulars, making progress by the use of deductive reasoning in a logical process that leads to certain (depending on the premise) knowledge. So, deduction proceeded from the general (self-evident truths and empirical generalizations) to the particular . . . ‘All men are mortal. Socrates is a man. Therefore Socrates is mortal’ (syllogism).

During the Scientific Revolution Aristotle’s widely-accepted deductive method was criticized by Francis Bacon (1561-1626) who insisted that the logical method of science should be induction. Science, Bacon-style, must proceed empirically. With repeatable observations of particular instances (including experiments, and data collection) we uncover regularities and patterns in nature. Induction turned Aristotle’s logic on its head. By amassing many particular instances it became possible to infer general patterns, principles, or laws. Aristotle’s starting point was a hypothesis: Bacon’s starting point was observation. Induction proceeded from the particular to the general and introduced a hint of doubt open to future investigation: ‘All observed swans are white. Therefore it is highly probable that all swans are white.’

These two approaches seem to encompass the logic of scientific explanation as the source of secure knowledge but they have different foundations: Aristotelian deduction starts with self-evident truths (universal laws) which lead to certain knowledge – but the conclusion does not add content to the premises. Baconian induction starts with empirical generalizations which lead to highly probable knowledge in which the conclusion adds content to the premises. Aristotle’s approach is sometimes described as ‘top-down‘ and Bacon’s as ‘bottom-up’. Aristotle’s approach is perhaps one of synthesis, starting with the whole and then finding out about the parts, while Bacon is an analyst, starting with the parts in order to form conclusions about the whole.

Deduction can only draw conclusions already present in the premises, while induction generalizes from evidence.

If these two approaches summarize crucial features in the logic of scientific explanation, then we should look at them in more detail.


While induction commanded a high degree of confidence, philosophers pointed out that its conclusions were always probabilistic. Induction could not guarantee or express the certainty we often associate with science. Philosopher David Hume (1711-1776) noted that all scientific knowledge depended on the ‘uniformity of nature’ – it assumed that things in the future would behave as they had in the past, and that this was, in a sense, an act of faith. Hume insisted that all scientific findings were thus contingent, not necessary. Hume’s tempering of scientific enthusiasm for absolute certainty has since become known as ‘the problem of induction’.

As an example of induction, in the early 18th century repeated observations in Europe and North America confirmed that all swans were white, an assumption that proved incorrect when, later in the century, Europeans observed black swans in Australia.

On this interpretation scientific facts were hardly different from the many inductive matters of fact that we accept in daily life, where from limited data we make general conclusions. Scientific facts were simply observations placed under greater scrutiny. Further, probabilistic truths do not sound very reassuring, even when the probabilities are extremely high. Induction did not seem to capture the certitude many people, scientists included, associated with scientific explanations.

In the 20th century there was a renewed attempt to establish those conditions that are individually necessary and jointly sufficient for an explanation to be described as ‘scientific’. This project became known as the ‘boundary problem’ as philosophers began looking once again at the logic of scientific explanation and the scientific standards of justification.

The hypothetico-deductive method (HD) & falsificationism

For English philosopher of science Karl Popper (1902-1994) to consider science as a form of inductive reasoning did science a disservice: science was stronger than inductive inference. After all, astrology can be justified using induction. Inductive reasoning gives only likely conclusions, so Popper returned to Aristotle’s claim that by using valid deductive reasoning, like that used in mathematics, secure premises will lead to secure conclusions, as in Aristotle’s syllogism about Socrates.

Popper thought that there was indeed a scientific method which he called hypothetico-deductive reasoning according to which a hypothesis (an empirical generalization) is established based on induction. This hypothesis is then rigorously tested by observation and experiment to deduce its consequences. If a hypothesis failed then a new hypothesis could be formed and tested by further experiment and observation. The path was (observation -> induction -> hypothesis -> deduction -> verification or falsification). This, Popper thought, was the special way that scientists deduce principles, laws, theories and regularities in nature.


Popper’s most potent idea was that scientific claims could be falsified or corrected. Conjectures could be refuted using deduction. A single valid refutation of a hypothesis was sufficient to overthrow that hypothesis. This could not be said for astrology. Using this ‘principle of falsifiability’ Popper in a famous book in the history and philosophy of science The Logic of Scientific Discovery (1959) set out to demonstrate that the so-called scientific theories of Sigmund Freud and Karl Marx were, in fact, pseudoscience because they could not be tested in a way that could confirm or falsify their claims.[1]

Falsificationism (the assertion that evidence cannot conclusively confirm, only falsify) has proved a powerful idea but is not without its critics. Does science proceed by falsification: is a theory abandoned when a counter-example occurs? Scientists do try to convince people that their ideas are true as scientific findings gradually become absorbed into the corpus of scientific knowledge rather than being regarded as hypotheses available for refutation. Science is embedded in auxiliary hypotheses so single cases of falsification are rarely treated as conclusive. Some disciplines in science, like taxonomy, appear to undergo modification rather than deductive refutation or falsification. Much of what is generally accepted as science does not follow the kind of principled procedure used in mathematics and logic.

The deductive-nomological method (DN) and inductive-statistical method

Another interpretation of the logic of scientific explanation was proposed by American philosopher Carl Hempel (1905-1997) at about the same time as Popper in the 1950s. Hempel’s version was called the deductive-nomological or ‘covering law’ model of scientific explanation according to which a scientific explanation must be deductive – aiming for true premises grounded in a general law. In this way the particular facts obeying a universal law explain the phenomenon (hence the expression ‘covering law’). Later Hempel extended his ideas to inductions from probabilistic observations as his inductive-statistical method.

Both Popper’s and Hempel’s conclusions fell victim to counter-examples. In Hempel’s formulation the facts and phenomena could be interchangeable when explanation is asymmetric. For example, the length of a shadow cast by a tree can be explained using the general laws of geometry and light travelling in straight lines. Following the deductive-nomological method we could swap the explanation and facts and say that the height of the tree can be deduced from the length of the shadow, the problem being that the length of the shadow does not explain the height of the tree.

HD proceeds not by induction but by means of a hypothesis stated in the form of a general law which deduces what will occur and then tests this hypothesis. In both HD and DN models the cause of a particular event is deduced from the initial conditions subsumed under universal or general laws. In both cases prediction and explanation are symmetrical. This became a broadly-accepted logical model for scientific explanation.

The more-or-less Aristotelian mode of reasoning from empirical generalizations serving as hypotheses, inserted into a deduction to yield results for particular instances (in modern form the HD and ND models), has been termed ‘foundationalism’. Even so, many philosophers of science are content to accept induction as a fair representation of how science proceeds.

One persistent difficulty has been that if biosocial phenomena are to be unified with physics and chemistry under a positivist program (the unification of science) then their methodology must be assimilated to this model. The last half century has demonstrated how difficult this has proved. We seem to be left with a dilemma. Either biosocial sciences are science in name only, or physics and chemistry are not foundational. Neither conclusion is palatable to a scientific community divided on this point. This is a problem that is being addressed in our times.

The lesson we appear to have learned from Popper and Hempel is that we can become diverted by the possibility of a unique ‘scientific method’ when of science. In practice scientists are not trained in logic. Science is problem-solving using the best possible means we can muster to get results, and at present this defies definition.

Let’s look a little closer at this pragmatic approach to science.

Abduction: inference to best explanation

Induction follows the form ‘all x’s in the past were y, therefore the next x will be y’. Sometimes explanations don’t seem to fall into some logical formula, they are much more diffuse – they simply seem to be the best way of accounting for all the available data. Arguments like this are referred to as inference to best explanation, strong inference, or abduction (attributed to American philosopher Charles Peirce (1839-1914). The somewhat derogatory translation of abduction as ‘best fit’ does not mean that scientific explanation is imprecise or logically weak. Newton had suggested as such in his Principia (1687) where he provided ‘Rules of Philosophizing’ one of these stating that ‘In experimental philosophy, propositions gathered from phenomena by induction should be considered either exactly or very nearly true notwithstanding any contrary hypotheses, until yet other phenomena make such propositions either more exact or liable to exceptions‘.

Today scientific explanation is treated as encompassing both inductive and deductive modes of explanation. Deduction is sometimes referred to as ‘top-down’ since it starts with empirical generalizations and gives us secure (some claim certain) knowledge about particular cases, while induction is ‘bottom-up’ since it starts with many particular observations that collectively provide evidence-based probabilistic generalizations.

Science & society

Karl Popper’s falsificationism is a valuable heuristic scientific methodology because it demonstrates the primacy of falsification over confirmation. Although it is not possible, with limited data, to prove that a theory is true, it is possible to prove that it is false. However, it has now become clear that science does not proceed in such a straightforward way. Scientists are not concerned with simply proving things false. In an influential book called The Structure of Scientific Revolutions (1962) another philosopher of science, American Thomas Kuhn (1922-1996) broadened the idea of what it was to be a science by showing how science is embedded in society as a pursuit among peers and that in historical reality its progress has not depended on single falsifying experiments or even a specific method, but more on ‘paradigm shifts’ of scientific opinion – the re-interpretations of past theories. Science at the time of Francis Bacon was seen as cumulative, each discovery adding a further brick to the edifice of scientific knowledge which proceeded in a linear fashion. Kuhn presented science more as a process of reconfiguration of existing structures rather than simple accretion: logical inference across paradigms was not simple. So, for example, Newtonian and Einsteinian mass are different in character.

The paradigm shift

Kuhn maintained that ‘normal’ science proceeds with a particular set of underlying assumptions for some time as tensions and incongruities build until new ideas become ‘incommensurable’[18] with the older ones, at which point a scientific revolution in thinking takes place in what Kuhn called a ‘paradigm shift’, a new way of framing a particular scientific problem.

Normal science has little time for philosophical questions but as consensus breaks down and paradigms come under serious challenge then underlying metaphysical assumptions tend to surface. Scientists do not abandon their theories the moment they conflict with the observed data – and for good reason.[2]

So, scientific change is related to a gradual revision of opinion among scientific peers rather than as a response to a single instance of falsification. Kuhn was pointing out that to some extent science is socially constructed and embedded, not just empirically verified.

And there were other concerns. Critics of Kuhn have pointed out that though physics may have proceeded the way he suggested as a transition from Newtonian mechanics to Einsteinian relativity and, later, quantum mechanics, other sciences did not evolve in the same way. Just as there had been problems with the assertion that science had a unique methodology so there were difficulties with the idea of the ‘paradigm shift’.

First, false theories can make true predictions (the Ptolemaic universe of cycles accounted adequately for movements of the stars and planets).

Second, a particular hypothesis depends on additional unproven hypotheses (auxiliary assumptions) to be sustained. Observation statements are embedded in theories, that is, they incorporate other theories and concepts. To say a car was travelling at 100 mph requires a prior common understanding of the concepts of distance, time, and velocity and in this sense it is a statement that is theory-laden. This is known as the Duhem-Quine thesis which draws attention to the way science develops not only through small incremental steps as discrete discoveries but also as a complete body of integrated knowledge with the robustness of one part being strengthened by the increasing robustness of others in a web of interdependencies.

Third, science in practice proceeds in a mostly inductive manner, being the result of persistent and wide observation. It is therefore more probabilistic in character, rather than deductive like mathematics, as Popper had claimed. Also, even accepting the notion of science as proceeding by paradigm shift, there is still a sense in which science is cumulative, even though there is not a strict accretion. New theories may re-cast the old, but they do not throw them out altogether. Each paradigm shift is not a totally new beginning but a reconfiguration of past conclusions to provide a more convincing explanation. In this sense it is building on the past (cf. Quine-Duhem) but not necessarily as simple accretion.

The scientific community

Scientific explanations are, in principle, open for all to access and understand as shared knowledge in the public domain. But who decides on what is good science?

Science proceeds by the scrutiny and review of evidence passing through the highly conservative and skeptical group of people we call scientists. The reputation of peer-reviewed scientific journals can of course rise and fall but the demand for quality science will ensure a high scientific standard. Accepted science, we might say, is the consensus of a jury of geeks with a collective attitude, not of faith, but of pervasive distrust until secure foundations have been established. By and large it is these geeks who make the calls about scientific standards … true, false, need more evidence, cannot answer the question (intractable).[7]

Part of science’s objectivity stems from scientists’ deep interest in their subject with personal gain low in priority. Success is measured in terms of factual outcomes not monetary gain … although research programs require money. Money once supplied by patrons or government is now coming increasingly from the corporate sector sometimes raising loyalty issues and increasing the temptation to put ‘results’ ahead of good science.

The scientific domain

It appears that we cannot conclusively isolate a single factor that is both necessary and sufficient to define what we mean by ‘science’. Perhaps we must accept that the activity of science entails a cluster of characteristics, most of which obtain for most of the time (there is a family resemblance) and many of the characteristics are shared by other disciplines. Science is a mixed-bag of laws, principles, practices, procedures, technologies, and other factors, all within a particular social context to which we apply the general portmanteau term ‘science’. Maybe an expression like ‘scientific domain’ conveys better what ‘science’ means to most people.

The notion of science as a body of interconnected ideas has become known as ‘coherentism’.

Here are some of the major characteristics of the scientific domain:

1. Testing of repeatable and falsifiable hypotheses by means of observations and carefully constructed and controlled and measurable experiments

2. The generalisation of specific findings into organised evidence-based factual knowledge in a way that reveals orderliness and patterns of dependence – the regular and predictable connections between events – presented as theories, laws, trends, principles, probabilities etc.

3. Insistence on the clarity of the logic and language used in scientific communication and explanation together with the rigorous monitoring (refereeing) of scientific publication within the scientific Community

4. Overcoming the biological limitations of our senses through the use of scientific technology like computers, scanners, microscopes, telescopes, particle accelerators and so on

5. Improving the theoretical framework of scientific techniques including the principles and practice of mathematics, electronics, engineering, surveying and so on

Together these factors yield discoveries and genuine progress over time as they build on the knowledge of the past

As with other subjects, including the humanities, science can be understood as the progressive extension and refinement of the categories we use to understand and explain the world. This ‘complexification’ of knowledge leads to the greater social complexity needed to manipulate nature in ever more effective ways.

We respect science’s impersonal disinterested universalism, critical scrutiny, and organised skepticism. There is no doubt that both today and in the past the precision of mathematics has also played a highly important and integral role in developing a scientific view of the world, both as a mode of deductive thought and inductive probability theory – although there are exceptions. It was not, for example, crucial to Darwin‘s theory of evolution by natural selection.


Over the last few decades a completely different approach to the ‘boundary problem’ has emerged. Maybe our preoccupation with science as an explanatory method has been completely misplaced. Perhaps a more productive approach would be to regard science as our most successful way of coming to grips with causes. Historically and philosophically causation has been suppressed as a major scientific theme. Empiricist philosophers harbor a deep suspicion of causality following the lead of Scottish philosopher David Hume in the 18th century. Hume had argued that causes were creations of the mind, being in fact merely the ‘conjunction of events’. Since the 1950s Hume’s contention has been taken less seriously but, even so, causation is an elusive concept that is currently being subjected to close philosophical conceptual analysis.

Being an area of active philosophical research with some promise, causality is discussed in two articles here.

Cumulative knowledge

Long before the advent of civilization and cities humans applied reason in their daily lives as they explored what could be eaten, how to track down animals . . . and so on. They recognized patterns in the world –  seasonal rhythms, the movement of the stars and so forth. These early humans were making observations and doing experiments that not only explained the world around them but which also made their lives easier, more efficient, and more productive. They were accumulating empirical knowledge that was the result of experiment and observation and this knowledge was passed from generation to generation by word of mouth so that future generations could take advantage of what had been learned. To us their efforts seem limited and faltering because today we have so much accumulated knowledge and its associated technology.

Thomas Kuhn drew attention to the way a paradigm shift reconfigures our entire understanding –  not only ideas but also our terminologies – so, for example, Newtonian and Einsteinian mass were defined differently. Scientific knowledge was not therefore always a simple matter of knowledge accretion: in moving from Aristotle, to Newton, to Einstein there were changes in understanding not just a build-up of facts.

Even so there is a strong sense in which mainstream factual scientific knowledge, outside grand theoretical revisions, is undeniably building on what has gone before. A subject like botany has not undergone the theoretical upheavals witnessed in physics and clearly has a strong cumulative character.

Science and technology are mutually beneficial: improved technology results in better science which can produce more sophisticated technology etc. When, on 4 July 2012, we celebrated the discovery of the elementary particle known as the Higgs boson (the God Particle, first theorized in 1964) remember that it was only about 350 years before that Englishman Robert Hooke amazed the world with illustrations of the weird and wonderful creatures he had seen using one of the first microscopes.

Industrial and technological improvements following on scientific advances opened up new worlds to scientific inspection, all this enhanced in recent times by the vastly improved information storage and retrieval possible with computation. When we look at science (and all factual knowledge) in this way it is clearly cumulative (even though theoretical ideas modify those of the past rather than building on them incrementally), as scientists refine our understanding of the world that exists both inside and outside our brains.

Accumulation of knowledge within a community requires communication as a major factor that must be taken into account. There are several key phases in human history relating to information and its communication: writing (on tablets, scrolls and codices) originating c. 3100 BCE and the development of mathematics, the use of paper and the printed book arising in China then in Germany in about 1450 CE, and today’s rapid information exchange resulting from data storage on computers since the 1970s, resulting in the internet, Big Data information sets, and artificial intelligence.

Eighteenth century philosophers were often conversant with a broad range of human knowledge: a philosopher was a good all-rounder. Today it is not possible to be even vaguely in touch with the general body of human knowledge. On 17 Aug. 2019 the English Wikipedia contained 5,911,308 articles.

Until relatively recently the total number of discrete academic disciplines studied in universities was in the tens. Today there are more than 50 separate disciplines dedicated to the mind and brain alone, and most scientists struggle to keep abreast of their own specialist discipline let alone taking an interest in others. One indication of the accretion of knowledge is the vast proliferation of technical words needed to carry out science, the relatively recent science of biochemistry alone adding many thousands of new words and concepts to our knowledge base as it has progressively refined the way we understand living things at the molecular level.

Secure knowledge

The historical development of science marks the progressive divergence of secure knowledge from a core of general and speculative learning. What began as a system of philosophy dealing with questions about what existed (ontology) what we can know (epistemology) and metaphysics (the nature of reality) over time crystallized into disciplines of secure knowledge: astronomy, mathematics, physics, chemistry, geology, and biology. These in turn would be extended to include political and social sciences, economics and so forth, each of these in turn diverging into yet more sub-disciplines.

In the 16th century botany diverged from medicine to become its own academic discipline. In the 17th century physics parted from metaphysics, in the 19th century Darwin’s work separated biology from theology, and in the early 20th century psychology was recognised as having scientific rather than philosophical foundations. Philosophy addresses those questions which science cannot answer, and why this should be so. In fact, the scope of philosophy has diminished over time, its degree of success being measured by the pace of its own demise.

Science historian David Wootton claims in his book The Invention of Science (2015) that

Modern science was invented between 1572, when Tycho Brahe saw a nova, or new star, and 1704, when Newton published his Opticks … there were systems of knowledge we call ‘sciences’ before 1572, but the only one which functioned remotely like a modern science, in that it had sophisticated theories based on a substantial body of evidence and could make reliable predictions, was astronomy, and it was astronomy that was transformed in the years after 1572 into the first true science . . . it had a research program with a community of experts.[12]

Drawing such clear historical boundary is courageous. The Scientific Revolution was a manifest turning point in human history but as a movement that rejected Aristotle they also owed him more than they cared to admit.

Analysis & synthesis

In very general terms we explain something either analytically by examining the structure and interaction of the parts, or synthetically in terms of the relation between the parts and a greater wholes. Though neither is necessarily to be preferred it seems that physics and chemistry tend to use the former, biology and the social sciences tend to use the latter. In the sense that deduction begins with secure knowledge (the placing of something within a general context) it is synthetic (top-down), while induction forms generalizations from multiple parts and in this sense it is analytic (bottom-up).


If we really must find a single key factor that gives science its strength then maybe we should draw attention to its ruthless skepticism and use of reason (as problem-solving and evidence assessment) as we apply the greatest possible objectivity that our brains can muster.

Reason requires no defense. The very fact of interrogating the concept of reason using reason presupposes the validity of reason.[20]

Rationality is a major factor in the attainment of all our goals. Whether it is possible for non-human organisms to exhibit some form of rationality is discussed elsewhere (see human-talk).

In 2021 Harvard Professor of cognitive science and public intellectual Steven Pinker published the book Rationality as a ‘cognitive toolkit’ for all people interested in reason (which he defined as ‘the ability to use knowledge to attain goals‘ where knowledge is ‘justified true belief‘).

Pinker’s book includes simply explained chapters on Bayesian decision theory, probability, critical thinking, correlation & causation, logic, game theory, and rational choice theory. Its relevance to science – and, indeed, all intellectual pursuit – suggests we all become familiar with these tools, regardless of our specializations and interests.[19]


In the 17th century the world of science underwent a radical transformation, the Scientific Revolution, as talk about four causes, four humours (and their four properties), and four temperaments gave way to the concepts of space, time, distance, force, and the related language of modern physics. Expressed crudely: numerology was replaced by mathematics, alchemy gave way to chemistry, magic and divination gave way to medicine, physic gave way to botany and medicine, and astrology gave ground to astronomy.

Then, for about 300 years, science was perceived as a special and unique kind of knowledge generated by a scientific method. This scientific method revealed facts about the world that were objectively true independently of human beings. The universe was matter in motion, and scientific investigation was gradually revealing more and more about its structure and operations on a journey towards a comprehensive and absolute account of reality. Thus, science was the progressive unlocking of absolute truth about the world as spectator-like scientists filled in the unknown details, like completing a crossword puzzle. They were, so to say, discovering what was in the mind of God at the time of the Creation.

In the 18th century German philosopher-scientist Immanuel Kant (1724-1804) expressed, in a compelling way, the view that, though there exists a world that is independent of human beings we only know that world as filtered through the biological limitations of our minds and senses (our innate biological capacities, Kant’s synthetic a priori). He pointed out that we do not know the external world directly (as noumena): what we know has passed through the mediation of our minds (as phenomena).

It is Kant’s ideas that are reflected in the general approach of modern science and its study of the phenomena of the natural world. When asked if two events in the world are simultaneous, or whether light consists of waves or a particles we do not feel scientifically cheated when we receive different and contradictory replies. We are also scientifically content to accept knowledge if it ‘works’ even if we find it difficult to comprehend, like quantum mechanics, or to know that what science tells us about space and time (scientific image) is very different from our common sense impression (manifest image).

Science, once regarded as the source of truth, is today regarded less as a body of eternal and absolute truths and more as a coherent conceptual network of strongly justified but corrigible beliefs. Talk of scientific truth is heard less often as we move from objective facts to ‘standards of intelligibility’ and ‘warranted assertability’.

The idea of complete scientific knowledge has been abandoned. We now acknowledge the presence of the human mind in our science, as amply demonstrated by relativity theory. Science does not provide us with final answers, it is defeasible – capable of endless refinement in the light of additional evidence.

In the quest for certain knowledge science does not provide final answers – but it is our most effective application of reason, logic, and evidence.[21]

Abduction, instrumentalism, coherentism & consilience

Today we can find no compelling candidate for a scientific method. Though scientific research shares general principles and procedures there is no clear demarcation between scientific knowledge and other kinds of knowledge, between science, non-science, and pseudo-science.

We make a distinction between natural and social sciences as ‘science’, while the study of classics, languages, literature, music, philosophy, history, religion, and the visual and performing arts are referred to as the ‘humanities’. The basis for this distinction is dubious, the connections between disciplines seeming to reflect the gradation of the organic world.  In the absence of certain knowledge we are left with secular empiricism – our best use of reason, logic, and evidence.

Science, though cumulative, is clearly not simple factual accretion since major scientific advances have entailed the reconfiguration of former understanding.

Our desire to compartmentalize and define has given rise to a host of -isms.


the view that scientific theories help us systematize observations and make effective predictions. cientific instrumentalism recognizes that our representation of reality is inescapably mediated by our perception and cognition but that, even so, this does not cast science into a world of relativistic subjectivity.


The combination of induction and parsimony or ‘inference to best explanation’.


The collection of evidence from all possible sources.

Subjectivity is always minimized by taking account of any potential cognitive bias. Each experiment is part of a world of interconnection and carries the caveat ‘other things being equal’ (ceteris paribus). The difficult process of learning what is objective and what subjective in our daily lives is aided by the application of science.

Without technology the world would be straightforwardly as we represent it with our senses. Science (including mathematics) and its associated technology has allowed us to explore this external world with an awareness of both the way our senses work as well as their limitations. Technology has taken us beyond the limitations of our biologically-given senses.

Scientific realism

The view that scientific theories describe both observable (planets and plants) and unobservable objects (electrons and space-time) as they truly exist, is referred to as scientific realism (naïve realism). 


As a view that science is, as it were, built on some form of sound foundations – as objects and/or ideas is steadily giving way to the following.

Coherentism & pragmatism

The view that (scientific) knowledge is simply a coherent set of justified beliefs. On this view any particular belief is connected with many other beliefs (beliefs are theory-laden), such that changing one belief entails an adjustment to all those that connect with it. Thus a justified belief is one that ‘coheres’ with our other beliefs (it is a relation of ideas). These beliefs tend to be confirmed or negated by the scientific community rather than individuals. Sometimes regarded as a form of holism – the view that

There are no foundations, just the strength that comes with interlocking ideas. We are reassured by the interlocking of ideas that provide mutual support. The best explanation (in any subject) is the one that coheres with our web of beliefs, not the one that grounds everything. In other words, facts are not necessarily grounded in foundational truths. American philosopher Quine offered the metaphor of our totality of knowledge having reason (a priori knowledge) at its centre and empirical knowledge at the periphery, though empirical knowledge could, in the extreme, penetrate to the core.

Historically foundationalists tended to accept that basic beliefs were fallible – that science is best understood as a process of constant refinement rather than the discovery of truth, and that beliefs had a strong interdependence. Coherentists acknowledge that some coherent systems of belief (e.g. religious versus scientific worldviews) were more coherent than others, claiming that realism and experiential beliefs provide the greatest coherence or justification, an experientialist foundationalism which coherentism in its original form denied: it wanted a privileged set of beliefs. The fusion of foundationalism and coherentism has become known as foundherentism (See Haack, 1993).

Science & trust

Science has demonstrated its power and validity through the way it allows us to understand and manipulate the natural world: its accounts are legitimated because they can be tested and are self-evident to anyone prepared to make the effort to understand them: they are not mysterious, transcendental, or restricted to a particular group of people. Above all its findings are not based on faith (belief without reason) – except faith in the ‘uniformity of nature’.

Most people trust scientists, not because scientists harness reason and use highly effective technologies and procedures as they pursue an improved cognitive taxonomy within the scientific domain – but because of the evidence of scientific activity that is all around us. Technology, as applied science, has provided our televisions, smart phones, cars, planes, space ships and armaments – all resulting from evidence accumulated over the history of humanity. Science is profoundly conservative and skeptical: there is no single unambiguous method that characterizes the way it proceeds, there is only a consensus of evidence within the scientific community.

Ultimately, we trust science through the collective intelligence of scientists. The role of reason and evidence are paramount but it does not seem possible to isolate something unique that makes their scientific application different from that used in other disciplines. A scientific conclusion is not derived by logic alone but also through empirical evidence evaluated by both inductive and deductive reasoning: it is peer-reviewed and provides a probabilistic conclusion that can be modified or overturned. What science searches for is accuracy, consistency, broad scope, simplicity and utility: in this it shares much with other disciplines.[10] For all these reasons we must be on our guard when science is hasty, politicized, or profitable – when it is under the influence of ideology or product.

Science, cognition, explanation

The view of science presented by cognitive scientists suggests that scientific reasoning is no different from any other kind of reasoning, it is simply the particular reasoning carried out within the constraints of the scientific domain. Science is the constant improvement of our mental models of ‘reality’ based on constant feedback using technology that has allowed us to extend the range of our senses far beyond that which we are given by nature and far broader in scope than that of any other living organism. Though we can never be fully acquainted with the world’s reality, our human reality, through science and its categories is constantly progressing as demonstrated by its practical outcomes.

So, science then, in a very general sense, is our best explanation of the natural world using cognitive taxonomy (reason as the refinement of our mental categories), and scientific progress as the steady improvement of the match between what our senses (including their extension through technology) tell us about the natural world and the natural world itself. To describe science as providing ‘objective truth’ or ‘mind-independent reality’ is probably over-ambitious. The world does not have our conceptual categories built into it – the categories we use are our most useful ‘human’ categories. How do we know that science is not just wishful thinking or some kind of mythology – how do we really know that science is grounded in something meaningful? Well, science walks the talk – we see it in the predictive power of science as manifest in computers, space travel, biotechnology, and modern medicine. Our survival as a species has depended, in part, on our science, so we cannot be doing too badly.

Limitations of science

The fact that science has overtaken many questions in philosophy might suggest that its scope is boundless, that it will eventually fill in all the unknown gaps in our knowledge. Areas traditionally placed beyond the reach of science include: maths and logic (the a priori formal disciplines that Hume referred to as ‘relations of ideas’); evaluative questions posed by epistemology, aesthetics, and ethics; interpretive questions in the humanities; and metaphysical assumptions of such generality that science can only get a foothold by depending on them. For example, that there is a real world independent of what we might happen to believe, and that we can sense this world and form conjectures about it. [16]

Science is sometimes characterized as the ultimate form of skepticism, doubting all claims about the material world unless thoroughly and rigorously tested and proved – but many people are skeptical about science itself. Perhaps climate science is ‘rigged’ and maybe the entire scientific enterprise is flawed: after all isn’t it science that has given us nuclear bombs, the environmental degradation resulting from modern technology, and the steady march into an artificial or virtual world that is taking us further and further away from our natural lifestyles and origins? People like this do not ‘believe’ in science. But scientists themselves trust their findings because they do not think of science as ‘belief’; it is much more than that. Belief is the domain of faith: it is believing in something without good reason . . .  or, at least, without demonstrable evidence.

Science is falsifiable. This corrigibility of scientific knowledge (openness to reform based on new evidence) is a potential source of both skepticism and humility: there is always room for doubt and improvement. In contrast, religion tends to bring certitude in the absence of evidence.

Science & order

Science investigates the existence of order in the universe. Where there is order there are reasons for that order. By providing reasons (as explanations) we are making the world intelligible. Science seeks the best reasons by minimizing human interest and influence in the interpretation of the world. Science does this by finding the circumstances (causes) under which other circumstances (effects) follow in a regular or predictable way. Reasons are closely related conceptually to purpose.

Science uses both inductive and deductive reasoning combined with experiment and observation to constantly refine the categories used within its domain – the names, principles, descriptions, laws, definitions, theories, laws etc. It is therefore the application of the most effective reasoning, practices, and instrumentation that we can muster all shared by publication and communication across the community of scientists in an attempt to understanding the world.

In the 19th century science was perceived as the mapping reality. Advances were achieved by discriminating nature’s pieces and then exploring their relationships, gradually heading towards a complete picture of the entire edifice of nature: it was like fitting together the pieces of a jig-saw puzzle as facts were read off the world. Scientific knowledge seemed objective, cumulative, and final. But in the 20th century it became clear that humans were not like detached observers discovering, as it were, the thoughts in the mind of god at the Creation. Instead, scientific knowledge is intimately bound up in the process of observation and interpretation. There can be no privileged perspective, only a human perspective: no incorrigible facts, and no absolute truth, only a set of increasingly effective theories.

Science has facilitated the construction of sophisticated scientific instruments that have greatly extended the human biological senses to give insight into the structure and process of matter. Technological advance is cumulative and progressive while theoretical advance, though building on knowledge of the past, can entail the reconfiguration of ideas.

Science is continuous with other methods of enquiry: there is no distinct ‘scientific method’ that establishes a clear demarcation between science and other domains of knowledge. The family of activities that fall under the rubric ‘science’ is now highly diverse: it uses many special tools that include scientific instruments, mathematics, logic, and a critical community of practitioners who monitor its procedures and publications.

Over the last two or three decades our view of science has changed. We have moved from viewing science as a seeker of truth and the ultimate reality of the world to regading it as a more instrumental or pragmatic endeavour. Science does not give us truth in the sense of absolute or ultimate knowledge and in this sense it is fallible. It does build on the knowledge of the past, though not in a simple process of accretion, and it is a system of knowledge. Above all it can be corrected – it is corrigible – and therefore open to endless refinement.

Central to the entire scientific process is our innate capacity for conscious self-correction, our reason. Through reason we can envisage possible futures and their consequences. This does not mean that we will choose futures that are desirable but it means that we have the capacity to do so.

The elegant science on which modern technology is built, the great edifice of explanation, testing, and description, did not come easily. The laws, patterns, principles and mathematics of nature on which our society rests are not self-evident – their power and secrets have been the result of a major investment of human thought and effort.

Although we might not agree with the way that scientific knowledge is applied, the progressive increase in scientific knowledge and resultant technology through human history appears beyond dispute. This strength of science is a constant reminder, even in the sphere of human affairs, to base our policies and action as much as possible on the empirical record, trying to avoid the temptation to moralise, criticise, or base policy decisions on our own particular ideology or grand narrative. Nowhere could this be more important than in the scientific foundations that underpin our future sustainability in which ideological stakes are seen as high for all stakeholders.

In humans ‘self-correction’ now depends on self-conscious and purposive actions based on reason and rationality within a cultural context. Today those humans likely to survive and reproduce are those that survive within an artificial cultural environment; culture has become more important than nature. Science is simply one aspect of the constant refinement of the ever-increasing number of categories we use to understand, measure and manage our surroundings – it is a product of the reason that can be seen in the process of ‘self-correction’ that has been with us since the first replicating molecules.

Science is a social practice that involves a community of experts with research programs that have established sophisticated evidence-based theories that can make reliable predictions. This is a present-day characterization of the emergence of science out of natural philosophy during the Scientific Revolution. But closer to the core of science is the awareness of our capacity to employ unfettered reason and this awareness came to us from the ancients. The capacity for mental self-correction is a biological adaptation translated into the mental realm.

Science is one special minded manifestation of the human capacity for self-correction that evolved out of mindless biological agency and its goals of survival and reproduction – the goals that ground human agency and its mindful goals of wellbeing and happiness.[13]

Key points

  • Scientific research is meritocratic, judged purely on the quality of the work, not who produced it
  • Science provides an explanatory context to the world – it is our most secure epistemology providing more reliable knowledge than any other discipline
  • Science attempts to represent (reflect, copy, map, grasp, mirror – choose your metaphor) as best it can, the external world that exists beyond our minds – but it can only do this within the constraints of our evolved perception and cognition assisted by technology (physical technology like microscopes, telescopes, computers etc. and mental technology like mathematics) that extend the range of our biologically-given senses.
  • Science proceeds on the assumption of a physical world that is external to ourselves – a world that persists after we die and which therefore exists independently of (but interpreted by) our collective and personal experience. This is a central dogma of science that can be referred to as scientific realism
  • Science is the refinement of scientific facts as increasingly corroborated beliefs embedded in shared scientific discourse
  • Science is defeasible: that is, it is not absolute and eternal knowledge or truth but is always open to challenge and improvement. This does not make it fictitious, a dream, a figment of our imagination, or even a modern myth or narrative: it is our best-authenticated epistemology
  • Science is empirical – it employs careful observation, experiment, and reason to draw conclusions about the material world – this form of knowledge acquisition dates back to the origin of man
  • Empirical scientific facts are not the way the world ‘is’ but statements of our beliefs about the world that improve our understanding and which can be tested, improved, and used to make predictions about the future
  • Philosopher Karl Popper claimed that scientific reasoning proceeded as hypothetico-deduction and that a single valid refutation of a hypothesis was sufficient to overthrow that hypothesis (falsificationism); today many would revert to the earlier view that, logically, it is induction based on the uniformity of nature
  • Philosopher of science Thomas Kuhn suggested that ‘normal’ science proceeds with the context of a scientific community accepting a set of underlying assumptions. Tensions gradually build up around existing theories until the new ideas become ‘incommensurable’ with the older ones, at which point a scientific revolution in thinking would arise as a ‘paradigm shift’, a new way of framing a particular scientific problem
  • Both the falsificationism and paradigm shift theories of the scientific process were found to be deficient: false theories can make true predictions; a hypothesis or theory usually depends on connected auxiliary unproven hypotheses so new discoveries are theory-laden and related to this is the fact that science proceeds not only through small incremental steps as discrete individual discoveries but also as a complete body of interrelated knowledge with the confidence in one part being strengthened by the increasing confidence in others; philosophers of science also now consider science as mostly inductive, simply the result of persistent and wide observation and therefore probabilistic rather than deductive like mathematics as Popper had claimed
  • In the absence of some unique and uncontroversial defining characteristic science is perhaps best understood in very general terms as a set of principles, rules, practices, procedures and technologies. Science is an activity with many characteristics – most of which are held in common for most of the time. Rather than thinking of science as something unique and special it is perhaps less confusing to speak of the ‘scientific domain’ (see list in text)
  • Scientific thinking is perhaps most simply characterised as reason applied in the most rigorous way within the scientific domain
  • Each organism perceives ‘reality’ through the limitations of its sensory apparatus. Humans have vastly extended their reality by creating technology that senses the world to both the smallest (particle accelerators) and largest (radio telescopes) scales while extending its mathematical capacity through the use of computers. Human reality is therefore more encompassing (wider in the scope of reality sampling) than that of any other organism
  • Much of science has been occupied with the discoveries that have followed the artificial extension of the natural capacities of our brain and senses by means of technology
  • Our experience of the world is unified and coherent. Our brains make sense of the world by pigeon-holing experience into categories that help us understand what is going on both within and outside ourselves. These categories can take many forms including: pictorial representations, names, explanations, definitions, descriptions, principles, theories, and laws. This constant process of mental classification we can call cognitive taxonomy. Some of these classifications, progressive classifications, are amenable to empirical refinement and improvement. Science can be characterized quite simply as the constant refinement of our cognitive taxonomy within the scientific domain
  • Science is simply one aspect of the constant refinement of the ever-increasing number of categories we use to understand, measure and manage our surroundings – it is a product of the reason that can be seen in the process of ‘self-correction’ that has been with us since the first replicating molecules
  • The body of scientific knowledge is cumulative, new advances building on the work of the past and adding new categories that help refine our cognitive taxonomy
  • Natural selection is a process of ‘self-correction’ that results in the adaptation of organisms to their environments. This is a totally mechanical process but we can see how ‘self-correction’ also becomes incorporated into behaviour as conditioned reflex, instinct and intuitive response, learned behaviour and eventually as a result of fully conscious deliberation. We can see here how life’s inbuilt mechanism of ‘self-correction’ (the trial and error of natural selection) has, through the evolutionary process, give rise to the self-conscious self-correction that we call reason, our accepted way of producing cultural change. For many people science is today’s most rigorous application of human reason to the world and this is what makes it ‘metaphysics that works’.


As an intellectual exercise the contents of this article can be used as a starting point to assess the relative merits of the following definitions:

Science is:

      • magic that works
        • the investigation of the natural order of the universe
          • the universally shared and accepted concepts for research and investigation
            • secular empiricism, defined as ‘the best use of reason, logic and evidence‘
              • Universal knowledge that transcends race, class, religion, gender, ideology, country etc.
                • the refining of the categories we use to describe the order of the universe – categories being statements that are maximally efficient explanations of the phenomena they describe
                • the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence (The Science Council)
                • any systematic field of study, or the knowledge gained from it
                • a body of facts or truths systematically arranged to show the operation of general laws
                • a system that uses observation and experimentation to describe and explain natural phenomena
                • knowledge based on the scientific method, a systematic approach to verification of knowledge first developed for dealing with natural physical phenomena and emphasizing the importance of experience based on sensory observation
                • our most rigorous application of reason to the explanation of the natural world
                • allowing the world to test our beliefs – a form of natural selection – an extension from pre-conscious to conscious selection

              Science timeline

              The following list is an aide memoire to major historical scientific events – listed mostly by scientific discoverers.

              3rd century BCE

              • 323–283 BCE – Euclid: wrote a series of 13 books on geometry called The Elements
              • 280 BCE – Aristarchus of Samos: used a heliocentric, heliostatic model

              2nd century BCE

              • 150s BCE – Seleucus of Seleucia: discovery of tides being caused by the moon
              • 150s Ptolemy: produced the geocentric model of the solar system.

              9th century

              • Al-Kindi (Alkindus): refutation of the theory of the transmutation of metals
              • 780-850 Al-Khawarizmi: wrote the first major treatise on Algebra titled “Al-jabr wal-muqabaleh”

              10th century

              • Muhammad ibn Zakarīya Rāzi (Rhazes): refutation of Aristotelian classical elements and Galenic humorism; and discovery of measles and smallpox, and kerosene and distilled petroleum
              • 984 – Ibn Sahl accurately describes the optics which became known as Snell’s law of refraction

              11th century

              • 1021 – Ibn al-Haytham’s Book of Optics. First use of controlled experiments and reproducibility of its results.
              • 1020s – Avicenna’s The Canon of Medicine
              • 1054 – Various early astronomers observe supernova (modern designation SN 1054), later correlated to the Crab Nebula.
              • Abū Rayhān al-Bīrūnī: beginning of Islamic astronomy and mechanics
              • Shen Kuo: Discovers the concepts of true north and magnetic declination. In addition, he develops the first theory of Geomorphology.

              12th century

              • 1121 – Al-Khazini: variation of gravitation and gravitational potential energy at a distance; the decrease of air density with altitude
              • Ibn Bajjah (Avempace): discovery of reaction (precursor to Newton’s third law of motion)
              • Hibat Allah Abu’l-Barakat al-Baghdaadi (Nathanel): relationship between force and acceleration (a vague foreshadowing of a fundamental law of classical mechanics and a precursor to Newton’s second law of motion)
              • Averroes: relationship between force, work and kinetic energy

              13th century

              • 1220–1235 – Robert Grosseteste: rudimentals of the scientific method (see also: Roger Bacon)
              • 1242 – Ibn al-Nafis: pulmonary circulation and circulatory system
              • Theodoric of Freiberg: correct explanation of rainbow phenomenon
              • William of Saint-Cloud: pioneering use of camera obscura to view solar eclipses[2]

              14th century

              • Before 1327 – William of Ockham: Occam’s Razor
              • Oxford Calculators: the mean speed theorem
              • Jean Buridan: theory of impetus
              • Nicole Oresme: discovery of the curvature of light through atmospheric refraction[3]

              15th century

              • 1494 – Luca Pacioli: first codification of the Double-entry bookkeeping system, which slowly developed in previous centuries[4]

              16th century

              • 1543 – Nicolaus Copernicus: heliocentric model
              • 1543 – Vesalius: pioneering research into human anatomy
              • 1552 – Michael Servetus: early research in Europe into pulmonary circulation
              • 1570s – Tycho Brahe: detailed astronomical observations
              • 1600 – William Gilbert: Earth’s magnetic field

              17th century

              • 1609 – Johannes Kepler: first two laws of planetary motion
              • 1610 – Galileo Galilei: Sidereus Nuncius: telescopic observations
              • 1614 – John Napier: use of logarithms for calculation[5]
              • 1619 – Johannes Kepler: third law of planetary motion
              • 1628 – William Harvey: Blood circulation
              • 1638 – Galileo Galilei: laws of falling body
              • 1643 – Evangelista Torricelli invents the mercury barometer
              • 1662 – Robert Boyle: Boyle’s law of ideal gas
              • 1665 – Philosophical Transactions of the Royal Society first peer reviewed scientific journal published.
              • 1665 – Robert Hooke: Discovers the Cell
              • 1668 – Francesco Redi: disproved idea of spontaneous generation
              • 1669 – Nicholas Steno: Proposes that fossils are organic remains embedded in layers of sediment, basis of stratigraphy
              • 1669 – Jan Swammerdam: Species breed true
              • 1672 – Sir Isaac Newton: discovers that white light is a spectrum of a mixture of distinct coloured rays
              • 1673 – Christiaan Huygens: first study of oscillating system and design of pendulum clocks
              • 1675 – Leibniz, Newton: Infinitesimal calculus
              • 1675 – Anton van Leeuwenhoek: Observes Microorganisms by Microscope
              • 1676 – Ole Rømer: first measurement of the speed of light
              • 1687 – Sir Isaac Newton: Classical Mathematical description of the fundamental force of universal gravitation and the three physical laws of motion

              18th century

              • 1745 – Ewald Jürgen Georg von Kleist first capacitor, the Leyden jar
              • 1750 – Joseph Black: describes latent heat
              • 1751 – Benjamin Franklin: Lightning is electrical
              • 1761 – Mikhail Lomonosov: discovery of the atmosphere of Venus
              • 1763 – Thomas Bayes: publishes the first version of Bayes’ theorem, paving the way for Bayesian probability
              • 1771 – Charles Messier: Publishes catalogue of astronomical objects (Messier Objects) now known to include galaxies, star clusters, and nebulae.
              • 1778 – Antoine Lavoisier (and Joseph Priestley): discovery of oxygen leading to end of Phlogiston theory
              • 1781 – William Herschel announces discovery of Uranus, expanding the known boundaries of the solar system for the first time in modern history
              • 1785 – William Withering: publishes the first definitive account of the use of foxglove (digitalis) for treating dropsy
              • 1787 – Jacques Charles: Charles’ law of ideal gas
              • 1789 – Antoine Lavoisier: law of conservation of mass, basis for chemistry, and the beginning of modern chemistry
              • 1796 – Georges Cuvier: Establishes extinction as a fact
              • 1796 – Edward Jenner: small pox historical accounting
              • 1796 – Hanaoka Seishū: develops general anaesthesia
              • 1800 – Alessandro Volta: discovers electrochemical series and invents the battery
              • 1800 – William Herschel discovers infrared radiation.

              19th century

              • 1802 – Jean-Baptiste Lamarck: teleological evolution
              • 1805 – John Dalton: Atomic Theory in (Chemistry)
              • 1820 – Hans Christian Ørsted discovers that a current passed through a wire will deflect the needle of a compass, establishing a deep relationship between electricity and magnetism (electromagnetism).
              • 1824 – Carnot: described the Carnot cycle, the idealized heat engine
              • 1827 – Georg Ohm: Ohm’s law (Electricity)
              • 1827 – Amedeo Avogadro: Avogadro’s law (Gas law)
              • 1828 – Friedrich Wöhler synthesized urea, destroying vitalism
              • 1830 – Nikolai Lobachevsky created Non-Euclidean geometry
              • 1831 – Michael Faraday discovers electromagnetic induction
              • 1833 – Michael Faraday is the first to observe a property of semiconductors.
              • 1833 – Anselme Payen isolates first enzyme, diastase
              • 1838 – Matthias Schleiden: all plants are made of cells
              • 1838 – Friedrich Bessel: first successful measure of stellar parallax (to star 61 Cygni)
              • 1842 – Christian Doppler: Doppler effect
              • 1843 – James Prescott Joule: Law of Conservation of energy (First law of thermodynamics), also 1847 – Helmholtz, Conservation of energy
              • 1846 – Johann Gottfried Galle and Heinrich Louis d’Arrest: discovery of Neptune
              • 1848 – Lord Kelvin: absolute zero
              • 1858 – Rudolf Virchow: cells can only arise from pre-existing cells
              • 1859 – Charles Darwin and Alfred Wallace: Theory of evolution by natural selection
              • 1861 – Louis Pasteur: Germ theory
              • 1864 – James Clerk Maxwell: Theory of electromagnetism
              • 1865 – Gregor Mendel: Mendel’s laws of inheritance, basis for genetics
              • 1865 – Rudolf Clausius: Definition of Entropy
              • 1869 – Dmitri Mendeleev: Periodic table
              • 1871 – Lord Rayleigh: Diffuse sky radiation (Rayleigh scattering) explains why sky appears blue
              • 1873 – Frederick Guthrie discovers thermionic emission.
              • 1875 – William Crookes invented the Crookes tube and studied cathode rays
              • 1876 – Josiah Willard Gibbs founded chemical thermodynamics, the phase rule
              • 1877 – Ludwig Boltzmann: Statistical definition of entropy
              • 1880 – Pierre Curie and Jacques Curie: Piezoelectricity
              • 1887 – Albert A. Michelson and Edward W. Morley: lack of evidence for the aether
              • 1888 – Friedrich Reinitzer discovers liquid crystals.
              • 1895 – Wilhelm Conrad Röntgen discovers x-rays
              • 1896 – Henri Becquerel discovers radioactivity
              • 1897 – J.J. Thomson discovers the electron in cathode rays
              • 1898 – J.J. Thomson proposed the Plum pudding model of an atom
              • 1898 – Marie Curie discovers polonium, radium, and coins the term “radioactivity”
              • 1900 – Max Planck: Planck’s law of black body radiation, basis for quantum theory

              20th century

              • 1905 – Albert Einstein: theory of special relativity, explanation of Brownian motion, and photoelectric effect
              • 1906 – Walther Nernst: Third law of thermodynamics
              • 1907 – Alfred Bertheim: Arsphenamine, the first modern chemotherapeutic agent
              • 1909 – Fritz Haber: Haber Process for industrial production of ammonia
              • 1909 – Robert Andrews Millikan: conducts the oil drop experiment and determines the charge on an electron
              • 1911 – Ernest Rutherford: Atomic nucleus
              • 1911 – Heike Kamerlingh Onnes: Superconductivity
              • 1912 – Alfred Wegener: Continental drift
              • 1912 – Max von Laue: x-ray diffraction
              • 1913 – Henry Moseley: defined atomic number
              • 1913 – Niels Bohr: Model of the atom
              • 1915 – Albert Einstein: theory of general relativity – also David Hilbert
              • 1915 – Karl Schwarzschild: discovery of the Schwarzschild radius leading to the identification of black holes
              • 1918 – Emmy Noether: Noether’s theorem – conditions under which the conservation laws are valid
              • 1920 – Arthur Eddington: Stellar nucleosynthesis
              • 1922 – Frederick Banting, Charles Best, James Collip, John Macleod: isolation and production of insulin to control diabetes
              • 1924 – Wolfgang Pauli: quantum Pauli exclusion principle
              • 1924 – Edwin Hubble: the discovery that the Milky Way is just one of many galaxies
              • 1925 – Erwin Schrödinger: Schrödinger equation (Quantum mechanics)
              • 1925 – Cecilia Payne-Gaposchkin: Discovery of the composition of the Sun and that Hydrogen is the most abundant element in the Universe
              • 1927 – Werner Heisenberg: Uncertainty principle (Quantum mechanics)
              • 1927 – Georges Lemaître: Theory of the Big Bang
              • 1928 – Paul Dirac: Dirac equation (Quantum mechanics)
              • 1929 – Edwin Hubble: Hubble’s law of the expanding universe
              • 1928 – Alexander Fleming: Penicillin, the first beta-lactam antibiotic
              • 1929 – Lars Onsager’s reciprocal relations, a potential fourth law of thermodynamics
              • 1932 – James Chadwick: Discovery of the neutron
              • 1934 – Clive McCay: Calorie restriction extends the maximum lifespan of another species
              • 1938 – Otto Hahn, Lise Meitner and Fritz Strassmann: Nuclear fission
              • 1938 – Isidor Rabi: Nuclear magnetic resonance
              • 1943 – Oswald Avery proves that DNA is the genetic material of the chromosome
              • 1947 – William Shockley, John Bardeen and Walter Brattain invent the first transistor
              • 1948 – Claude Elwood Shannon: ‘A mathematical theory of communication’ a seminal paper in Information theory.
              • 1948 – Richard Feynman, Julian Schwinger, Sin-Itiro Tomonaga and Freeman Dyson: Quantum electrodynamics
              • 1951 – George Otto Gey propagates first cancer cell line, HeLa
              • 1952 – Jonas Salk: developed and tested first polio vaccine
              • 1953 – Crick and Watson: helical structure of DNA, basis for molecular biology
              • 1963 – Lawrence Morley, Fred Vine, and Drummond Matthews: Paleomagnetic stripes in ocean crust as evidence of plate tectonics (Vine-Matthews-Morley hypothesis).
              • 1964 – Murray Gell-Mann and George Zweig: postulates quarks leading to the standard model
              • 1964 – Arno Penzias and Robert Woodrow Wilson: detection of CMBR providing experimental evidence for the Big Bang
              • 1965 – Leonard Hayflick: normal cells divide only a certain number of times: the Hayflick limit
              • 1967 – Jocelyn Bell Burnell and Antony Hewish discover first pulsar
              • 1983 – Kary Mullis invents the polymerase chain reaction, a key discovery in molecular biology.
              • 1986 – Karl Müller and Johannes Bednorz: Discovery of High-temperature superconductivity
              • 1994 – Andrew Wiles proves Fermat’s Last Theorem
              • 1995 – Michel Mayor and Didier Queloz definitively observe the first extrasolar planet around a main sequence star
              • 1995 – Eric Cornell, Carl Wieman and Wolfgang Ketterle attained the first Bose-Einstein Condensate with atomic gases, so called fifth state of matter at an extremely low temperature.
              • 1997 – Roslin Institute: Dolly the sheep was cloned.
              • 1997 – CDF and DØ experiments at Fermilab: Top quark.
              • 1998 – Supernova Cosmology Project and the High-Z Supernova Search Team: discovery of the accelerated expansion of the Universe / Dark Energy.
              • 2000 – The Tau neutrino is discovered by the DONUT collaboration

              21st century

              • 2001 – The first draft of the Human Genome Project is published.
              • 2003 – Grigori Perelman presents proof of the Poincaré Conjecture.
              • 2006 – Shinya Yamanaka generates first induced pluripotent stem cells
              • 2010 – J. Craig Venter Institute creates the first synthetic genome for a bacterial cell.
              • 2012 – Higgs boson is discovered at CERN (confirmed to 99.999% certainty)
              • 2012 – Photonic molecules are discovered at MIT
              • 2014 – Exotic hadrons are discovered at the LHCb
              • 2015 – Kepler 438b discovered to have similar Earth-like properties
              • 2015 – Traces of liquid water discovered on Mars

              Media Gallery

              Philosophy of Science | Four Major Paradigms

              Research HUB – 2019 – 11:09

              Three Theories of Truth (Correspondence, Coherence, Pragmatic)

              2020 – 18:52

              Why Use Reason?

              Kane B – 2021 – 28:07

              What is Truth?

              Closer to Truth – 2020 – 26:46

              Classification and Kinds: An Antirealist View

              Kane B – 2020 – 1:10:03

              The language of nature

              Kane B – 2021 – 59:45

              David Deutsch – What is Truth?

              Closer to Truth – 2016 – 10:21

              Hilary Putnam on the Philosophy of Science (1977)

              mehranshargh – 2015 – 43:56

              First published on the internet – 1 March 2019
              . . . revised 2 December 2020
              . . . revised 27 July 2022


              Omega or Swan Nebula
              Photograph NASA’s Hubble Space Telescope located about 5500 light-years away in the constellation Sagittarius.
              Courtesy Wikimedia Commons – NASA, ESA and J. Hester (ASU) 2003 – Accessed 15 October 2020

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