From its systematic birth in the 17th century, modern science became a source of perplexities. Kepler and Galileo were convinced that nature is like a book written in mathematical language. But Newton's entrenchment of physics rightly led to doubts that this was the whole story: how to explain that highly abstract and sophisticated theoretical constructs could be successfully applied to the real world? This question became a puzzle that provided philosophers with abundant material for their speculations.

Justificationist philosophies

René Descartes, at the dawn of modern science, had established that only a knowledge demonstrable according to the model of mathematics could be considered true science. Convinced that such a science exists, he asserted that its instructions should be self-evident truths about which no doubts could be raised.

In the 18th century, English empiricism, taken to its ultimate consequences by David Hume, asserted that the validity of universal statements cannot be proved by recourse to experience, since experience provides only concrete data , and no logical process allows one to go from particular data to general statements. The status was paradoxical. Indeed, despite the undoubted success of science, it would not be possible to claim that its laws provide an authentic knowledge about reality. Just as experimental science was beginning to take hold, its foundations seemed to crumble.

In his Critique of Pure Reason of 1781, Kant tried to bridge the contradiction. He was convinced, like Descartes, of the necessity of proving any knowledge that presented itself as scientific, by establishing certain instructions . He also believed that Newton's physics was true science and final. However, he was impacted by Hume and concluded, like him, that induction from experience is invalid. Considering that scepticism was inadmissible, he found a rather ingenious solution: since the basic principles of science could not be supplied by experience, it would have to be admitted that they are supplied by the scientist. In other words, he admitted that the human knowledge is based on a set of concepts and laws that would be a priori, i.e., independent of experience, and that would provide the background against which the data of experience would be placed. This implied that these concepts were present in any person and that, when correctly applied to experience, precisely the fundamental laws of Newtonian physics would be obtained.

Conventionalism

In the late 19th and early 20th centuries, the formulation of non-Euclidean geometries and the theory of relativity showed that Newtonian physics did not have the universal validity that Kant attributed to it. Moreover, the problem of induction remained like a phantom that prevented attributing certainty to the claims of experimental science.

In these circumstances, the well-known physicist Henri Poincaré concluded that, in reality, scientific laws are neither true nor false. They would simply be conventions or stipulations that would be supported by their consequences. agreement This solution was in line with the spirit of the positivism of the time, which renounced knowing the true causes of facts and asserted that science should limit itself to establishing relationships between observable phenomena, describing any further pretensions as impossible metaphysics.

Such ideas still supported the justificationist conception of science. Conventionalism was a natural consequence if one thought that true science should be justified by strict demonstrations, and that experience does not permit the formulation of such proofs. Moreover, once it was known that Newtonian physics was only a partial science and that its value was not definitive, there seemed to be no obstacle to upholding conventionalist ideas.

Critical rationalism

In 1934, Karl Popper published his first book, in which he claimed that theories can never be justified, but that knowledge can be augmented by critical examination of them. The procedure would be as follows: while experience cannot prove the truth of any theory, a theory that contradicts experience must be false. Therefore, we could never be certain of reaching the truth, but sometimes we could detect the error. The knowledge would progress thanks to the detection of errors and the consequent formulation of new and improved theories. But theories would always be hypotheses or conjectures that would never reach the status of proven truths. All knowledge would be conjectural, even if it could be progressive.

The basic outline of the augmentation of knowledge would, according to Popper, follow the method of essay and elimination of error. Theories would not come from experience and would not be proved by it. Popper is thus in line with Kant. However, unlike Kant, he claims that theories are free creations that can be modified and are not based on fixed and immutable categories.

In successive works, Popper drew a parallel between the progress of knowledge and Darwinian biological evolution. Both processes would follow the same basic outline of essay and elimination of error, with the difference that, in evolution, what emerges and dies are living beings, while in science it is theories. In both cases there would be a similar process of emergence of new Structures, selection that would eliminate the less adapted ones, and survival of the most competitive ones. provisional of the most competitive.

Philosophy and biology

Until well into the 20th century, philosophy of science had focused primarily on physics, the most exact and successful science. Biology, however, was becoming increasingly important in research.

In two papers published in 1941 and 1943, Konrad Lorenz took up the Kantian theory of a priori forms and categories as the condition of possibility of experience, and tried to explain how these Structures arise in the evolutionary process of mutation, selection and adaptation. He claimed that all living things possess innate Structures from knowledge, which are a result of the evolutionary process and act as inherited dispositions that make information utilisation and adaptation possible. Like the Kantian Structures , they would be a priori conditions of knowledge; however, being products of evolution, they would not be immutable but changeable. Moreover, the evolutionary process would be equated with the process of augmentation of knowledge, in that both would involve the emergence of new entities subject to selection, elimination and adaptation: the two processes would follow the common path of tentative formulation and adaptive selection.

Such a conception is very similar to the basic outline of essay and error elimination used by Karl Popper. In 1974, Donald Campbell developed this outline from a biological perspective, using for the first time the degree scroll of Evolutionary Epistemology. The ideas of Lorenz, Popper and Campbell were systematised by Gerhard Vollmer from 1975. The result is a perspective that shifts epistemology from an almost exclusively physics-centred approach to one in which biology is central.

Evolutionary Epistemology

Evolutionary epistemology is presented as a perspective that claims to be the most important advance in the Philosophy of science since the 18th century. There is already an abundant bibliography on topic, both favourable and critical. The work edited by Gerard Radnitzky and W.W. Bartley III collects four writings by Karl Popper and Donald Campbell, which provide the foundations of the theory, together with fourteen others that broaden the horizons and respond to criticisms.

The central idea of evolutionary epistemology is to approach the problems of the theory of knowledge from the perspective of biological evolution. In particular, the original question about the validity of knowledge is answered by resorting to biology: our knowledge is said to correspond to reality because we are living beings descended from others who, in the process of evolution, have survived because they had developed capacities of perception and learning adapted to the environment. In this way, ancient philosophical questions receive an answer that is presented as scientific. In this sense, Vollmer states that "after all, science is Philosophy with new means".

Of course, there is no difficulty in admitting that some problems, once regarded as philosophical in a confused way, have later been successfully tackled by experimental science. Just think of the ancient theories about the nature of the stars or the composition of the subject. Nor is it difficult to recognise that experimental science and Philosophy are closer than might at first sight appear, since both seek and obtain a knowledge of reality by resorting to experience and logical reasoning. It even seems desirable to re-establish the link between the two perspectives, since the fragmentation of knowledge into incommunicable worlds is one of the main causes of the crises in today's culture. However, greater problems arise if we ask ourselves about the validity of the basic outline of evolutionary epistemology.

Emergency and the human person

result Indeed, in order to explain the value of knowledge, is it sufficient to suppose that our capacities are the result of a process of selection and adaptation, and would this process allow us to explain intelligence, which is associated with the capacity to formulate theories and submit them to rational criticism?

If we limit ourselves to the case of man, attempts to explain our intellectual capacities by means of simple evolution encounter great difficulties. Rosaria Egidi studies the topic of emergence, noting that it does not deal with ontological problems, and devotes only four pages to it. Karl Popper tries to explain how the human mind would emerge in the evolutionary process, recognising that there are few elements available and that he must content himself with formulating very hypothetical conjectures. This can only be so, because human capacities go far beyond the level of the material. Popper recognises this, but does not take the logical step of admitting the existence of the spirit as something that refers to something beyond nature and which can only be a God staff creator.

Such a step may seem unscientific to some advocates of evolutionary epistemology. However, if man is to be studied rigorously, it is unavoidable. Of course, it is a step that transcends the limits of experimental science. But this does not authorise us to try to explain the human person without considering spiritual realities, as if this were a consequence of scientific rigour. Rather, rigour requires that, when one reaches the boundaries of the method one uses, one does not overstep those boundaries.

Pan-criticism

Another major difficulty hangs over Evolutionary Epistemology, and that is: is it possible to claim that everything knowledge is conjectural and to continue to talk about the truth and progress of knowledge?

This difficulty has accompanied Karl Popper's Philosophy from the very beginning. Around 1960, W.W. Bartley proposed a solution which he called comprehensive critical rationalism and, more recently, pancriticism. It consists of showing that there is no contradiction in affirming the hypothetical character of all knowledge if it is also admitted that this same thesis is hypothetical. In final, it is underlined that, since it is not intended to justify the definitive value of any knowledge, there is nothing to prevent reasoning always in a hypothetical way.

Bartley's arguments are not even accepted by all Popperians. Undoubtedly, they show a great argumentative capacity, and they use reasoning full of subtleties. But the difficulties they encounter are remarkable, and even more so when what is at issue is whether everything, including the most basic criteria of our knowledge, can be and even should be subjected to criticism.

The Philosophy of Popper and his followers is mainly situated in the coordinates of rationalism and empiricism. These positions have serious flaws which are skilfully highlighted by Popperianism. But that is not enough. In order to sustain a realist theory of truth, the metaphysical dimensions need to be seriously addressed, and this subject of issues is often treated in a fragmentary and insufficient way in the Popperian perspective. Popperian epistemology has interesting methodological insights and provides valuable tools for the analysis of some questions of the Philosophy of science, but it poses serious difficulties if one tries to build on that basis an entire Philosophy, and that is what Popper and his orthodox followers seem to be trying to do.

Once again, Popperian epistemology sample its virtualities and its limitations. It provides provocative and interesting insights, presented in a straightforward and understandable style, but its validity seems more limited than some of its advocates claim.

1. Evolutionary Epistemology, Rationality, and the Sociology of Knowledge, edited by Gerard Radnitzky and W.W. Bartley III. Bartley III. Open Court, La Salle (Illinois) 1987.