Doubtful Philosophies of Science

Philosophical Reflections XXXI

Part A: Uncertainty

Science is a derivative of the more general method of induction, characterised by its specific approach and methodology. As such it is subject to all the rules and considerations pertaining to inductive reasoning in general. Of particular note is the contextual certainty achievable by induction. As inductive reasoning results in certainty, so too does science. For example, the existence of atoms is not some kind of probabilistic estimate that might be overturned by new findings tomorrow, but a proved, certain, objective fact. The definition and methodology of science derive from and reveal its philosophical basis: that reality (the subject of science) exists, that we can know it (the purpose of science), and we know it by objective means (the methodology of science). The success of science is (and can only be) a consequence of its ability to achieve truth, which itself is a consequence and demonstration of the truth of these philosophical underpinnings. Yet modern philosophy is dominated by a pretence that we can know nothing, revelling in doubt as its alternative to understanding and explanation, and one symptom is the state of the philosophy of science. While science has been progressing at a staggering rate – from the Wright brothers to supersonic jets, from rockets to men on the moon, from the discovery of DNA to sequencing the human genome, each in a matter of decades – mainstream philosophies of science see only doubt. Rather than explain the success of science, they attempt to undermine it with claims that nothing is certain and that all science is tentative, if not imaginary. We now turn to such claims.

Falsifying Paradigms

The most popularised and widely known philosophies of science are those of Karl Popper and Thomas Kuhn. We will briefly analyse these in the forms in which they are generally understood and promulgated. The essence of Popper’s philosophy of science is that a valid scientific hypothesis or theory is necessarily falsifiable but inherently unverifiable. This is because if theory A makes a prediction B(If A then B), then the rules of deductive reasoning mean that if B is false, A must be false; while in contrast B being true does not prove A (a true conclusion does not imply true assumptions). Popperianism concludes that science can never be certain of anything, and a valid scientific theory is one which is open to disproof – not one that has been proved, because that is impossible. The potential for disproof is the best we can do to link our theories to reality, and thus is the defining quality of science. The essence of Kuhn’s philosophy of science is that science consists of a series of paradigm shifts. That is, there is a progression of accepted theories (paradigms), each of which has its heyday before facing increasing data to the contrary, finally crumbling – generally when its adherents die or retire. It is then replaced by a new paradigm fitting the new data – until it too is superseded in the same manner. For example, the geocentric model of the solar system was replaced by the heliocentric model which was refined to a heliocentric system with elliptical orbits, and the “static” paradigm of the cosmos was replaced by the “steady state” paradigm of an eternal expanding universe which was replaced by the “big bang” paradigm, which will be replaced by something else. Thus Popperianism recognises that science must be tied to reality, but starting from the primacy of deduction, and finding no certainty of proof there, it consoles itself with the certainty of disproof. Meanwhile, Kuhnianism sets science adrift in a sea of ignorance, with “truth” an elusive and illusory construct that fits the facts of today but not the facts of tomorrow, depending more on the subjective bias of scientists than on objective facts. In contrast, a philosophy of science based on an objective epistemology – itself a consequence of the manifest hardness of reality (see Philosophical Reflections 1-3 ) – starts from the primacy of induction and ends in the achievement of certainty.

The Kernel of Truth

Induction and contextual certainty were detailed in Philosophical Reflections 24-27, and we don’t need to repeat the proofs in detail here. But basically, because things in reality have a nature which affects the things around them, and different things in reality share all or some aspects of their natures, all we know and can know comes ultimately from inductive reasoning, and within the context of our observations, inductive reasoning gives us certain knowledge of the nature of things. That is, while we don’t know everything, what we know, we know – and the rules of inductive reasoning enable us to know the limits of our knowledge, so that we can know that we know it and why we know it. Robotic probes do not escape Earth and investigate Jupiter by luck, and smallpox was not eradicated by chance or wishful thinking. In the face of such eloquent proofs of the efficacy of science, how do philosophies of doubt remain standing? Like all good lies, both the Popperian and Kuhnian philosophies of science are partly true. But what is true about them is true not because their premises or arguments are true, but as consequences of the wider principles of induction. A theory which makes no predictions about what will happen is cut off from the realm of evidence and therefore is essentially arbitrary, hence without value. Conversely, any theory which does make predictions is by definition testable. If such a theory is correct, it will pass the tests; if not, eventually it will fail. Thus the primary feature of valid scientific theories is testability, of which falsifiability of incorrect ideas is a corollary not the primary. And for the reasons explained when discussing inductive reasoning, the result is not perpetual uncertainty but increasing certainty. For example, ordinary matter is composed of atoms, which do consist of a small, dense positively charged nucleus surrounded by electrons in orbital “clouds”, clouds whose structure determines the chemical properties of atoms, which in turn determine the properties of matter. As science progresses, we will learn more about this and why it is so: but the knowledge we have now is certain. We will find out more about the fine details of what atoms are, and why atomic nuclei are what they are and electrons do what they do: but we will never find that ordinary atoms don’t after all have that structure. Similarly, the history of atomic theory could indeed be described as a series of “paradigm shifts” – from pre-atomic theories, to atoms as little balls, to atoms as little puddings of positive and negative charges, to atoms as a tiny central nucleus with orbiting electrons, to the modern understanding of electron “shells” and quantum mechanics. But these are not random jumps through a sea of ignorance, but the proof of the existence of atoms at the expense of other ideas, then proof that they contained positive and negative components, then further refinements in the light of observed reality toward a theory of increasing detail, accuracy and precision. Such a process, in basic form, is echoed in all branches of science, and is a consequence of the fact that we learn about reality by observing it, generating theories, and testing them. As a result, we have progressed from guesses and speculations about the fundamental nature of matter, to the ability to see and move individual atoms (e.g. with atomic force microscopes), and even to create designer atoms to improve our lives (such as certain medical isotopes).

Contradictions

In addition, it is worth noting that both the Popperian and Kuhnian philosophies of science suffer from internal contradictions. Regarding the former, as all knowledge of the world ultimately must come from induction (reason applied to sensory evidence), the very data which is used to “falsify” a theory is itself derived from induction. So if one claims that induction is never certain, no theory can be disproved either! Falsifiability is only possible as the flip-side of inductive certainty: thus Popperianism in fact rests on an assumption of inductive certainty which it then evades. The crucial question on paradigm shifts is why, in fact, do they shift? The answer is: because while earlier observations were consistent with the theory, further ones were not. But then the next paradigm must account for both the former set of observations and the latter. And so on. Thus, each paradigm is a better explanation of more facts of reality than the previous – which is a finite progression. Eventually we must settle on a complete and confirmed paradigm, or at worst, one in which the areas of ignorance are clearly defined. The less we know about something, the wilder our guesses to explain it and the bigger the “paradigm shifts” that result. Examples of that are what give Kuhnianism a veneer of plausibility. But by the nature of facts and truth, no fact can ever falsify a true theory: which can therefore never be caused to “shift”. Eternally shifting paradigms are only possible if there are no true theories, which is only possible if there are no facts of reality to describe – but there are. Which is why science works, and works so well.

It’s Just a Theory!

Scientific knowledge is dynamic, and the changing landscape of facts and theories mirrors the valid aspects of falsification and “paradigm shifting”. It is worth a closer look at the elements that comprise scientific knowledge, to illustrate the boundary between knowledge and doubt, and to dispel misunderstandings that have been used to attack science. For example, creationists often say that “evolution is just a theory”, as if theories are some kind of inferior, dubious alternative to facts. Such an attitude to theories is common, but it is a critical misunderstanding of science, of which theories are a crucial component (see Philosophical Reflections 30, on the nature and process of science). Scientific statements can be divided into facts, laws, theories and hypotheses. A fact is some proved item of knowledge, such as “water is a compound of hydrogen and oxygen” or “Earth is a planet orbiting the Sun.” A law is a general descriptive principle that applies to all relevant existents. Thus a law describes a fundamental quality of a broad range of things. For example, the law of universal gravitation applies to all mass, and the laws of thermodynamics apply to all systems of matter and energy. A theory is a causal description that explains facts. For example, the atomic theory explains the chemical qualities of elements and compounds, and the theory of evolution explains the origin of the multitude of kinds of living things. A theory is not some weaker second cousin of a fact, but an explanation of facts. An hypothesis is a proposed explanation of facts, essentially a provisional theory. A “good” hypothesis is one which explains some facts, does not absolutely contradict any other facts (though it might not be able to explain everything), and makes testable predictions. Hypotheses abound at the interface between what we know and what we don’t know, like expendable scouts probing a wilderness. It is plain from the above that whereas hypotheses are never facts (though they might become facts), both laws and theories can also be facts, indeed wider-ranging and more fundamental facts than the specific facts they encompass. For example, the atomic theory is also a fact, as it is a fact that elements and compounds are made of atoms. In contrast, hypotheses by their nature never have enough evidence to be called “true”: but the generation of hypotheses is how theoretical science progresses. Many hypotheses fall by the wayside, but by spotlighting where further observations should be made, even the wrong ones can contribute to the growth of knowledge. It is out of the melting pot of facts, hypotheses and experiment that validated laws and theories are refined. Thus we can see how science grows by objectively looking at reality, and as it grows, we see ignorance give way to knowledge by the primary process of induction – which entails the secondary effects of falsification and paradigm shifts of wrong or incomplete ideas. In a way, science is like a city growing in a wilderness. The edges are in great flux as knowledge extends in fits and starts into the unknown, while the established centre grows in height and maturity of understanding, filling in details and rebuilding where required. Einstein once said in a similar vein:

Creating a new theory is not like destroying an old barn and erecting a skyscraper in its place. It is rather like climbing a mountain, gaining new and wider views, discovering unexpected connections between our starting point and its rich environment. But the point from which we started out still exists and can be seen, although it appears smaller and forms a tiny part of our broad view gained by the mastery of the obstacles on our adventurous way up.