What is philosophy of science?

Modern science today encompasses countless areas or disciplines that seem distinct from one another. On one side, we have the so-called hard sciences: physics, chemistry, biology, and mathematics, although the latter is often seen as being of a different nature from the other three. On the other side, we have the human sciences, which are said to be speculative, far from experimentation, lacking the generality and cohesion expected of scientific disciplines—thus, they have been called soft sciences in contrast to the former. The philosophy of science has dealt with both hard and soft sciences, but the bulk of research has concentrated on the former, especially physics, which philosophers consider the model or paradigm of experimental science. I do not wish to discuss here whether the social sciences represent knowledge of a different nature than hard sciences, which would lead us to the debate over the fairness of comparing social sciences to hard sciences and then labeling them as soft. For now, I only want to mention that, at least programmatically, the philosophy of science also includes the so-called social sciences, although studies on them by philosophers of science are not as abundant as those on other sciences.

Are astrology, palmistry, superstitious beliefs, or indigenous worldviews subjects of study in the philosophy of science? They are only insofar as the philosophy of science attempts to draw the line between what is scientific and what is not, but no further. Determining what is science and what is not is, of course, one of the problems of the philosophy of science. However, initially, it takes the concept of science for granted. It assumes that physics, mathematics, and other disciplines embody scientific knowledge and then reflects on various aspects of them. From there, general questions arise—questions about characteristics common to all sciences. What do physics, chemistry, biology, and mathematics have in common? What do Galileo’s refutation of Aristotle’s theory of weight-acceleration relations and Pasteur’s refutation of spontaneous generation have in common? What do the development of the theory of elliptical planetary orbits and the understanding of the atom's internal structure share? As the philosophy of science delves into such questions, it ultimately confronts issues related to the scientific method, hypothesis formulation, measurement, mathematization, scientific explanation, prediction, experimentation, the relationship between theories and the world, induction and deduction, scientific communities, and the role of biases in theory development, among other topics.

However, the philosophy of science can be more specific. It can focus on a single discipline. How is truth determined in mathematical knowledge? What are the differences between actual and potential infinity? Should numbers be understood as classes, functions, or constructions from basic intuitions, as Brower believed? These are specific problems in one branch of the philosophy of science: the philosophy of mathematics. The same can be done for each hard science, allowing us to find philosophy of physics, chemistry, biology, etc. Specialization also leads to comparisons between disciplines, raising questions about whether some sciences are reducible to others, whether certain theories can be extrapolated to other fields of knowledge, or at least offer guidance on how theories should be structured in those other fields. This gives rise to problems such as whether chemistry is reducible to physics, whether the probabilistic models of quantum physics can be applied to predicting human or social behavior, or whether there is a difference in nature or degree between mathematics and other disciplines. Thus, the various fields of study within the philosophy of science are completed.

Therefore, we can now offer a vague definition of the philosophy of science. It studies scientific knowledge—its nature, structure, function, relation to the world, importance, as well as the procedures, discovery or invention stories that lead to such knowledge, scientific communities, and how they behave and relate to their surroundings. This can be done either on a general level or a specific one, often comparing, distinguishing, and sometimes extrapolating. As we can see, the subject matter of the philosophy of science is vast, but even so, it is just one branch of philosophy in general. If I could decide, I would say that it is a branch of other branches, if the internal division within philosophy makes any sense at all.

Among those approaching the philosophy of science, a concern about its usefulness often arises. What is the purpose of the philosophy of science? Why study it? Assuming these are not rhetorical questions born out of laziness or a lack of interest in philosophy, we should remember that usefulness is often a matter of creativity. Becoming aware of aspects of scientific knowledge can make us more tolerant of beliefs we consider superstitious, although for some, it only makes them more sectarian. It may improve the performance of scientists by making them aware of the intricacies of scientific knowledge, although for some, it may be confusing and distract them from their goals. However, most who engage in the philosophy of science do not do so because of its utility, nor are they concerned with finding applications. They do it because they enjoy seeing and understanding, because they like to gain clarity on these matters. They are intrigued by scientific knowledge, they take pleasure in its formulas, its heroic stories, its discoveries and applications. They want to know why scientific knowledge works, whether it is the only form of knowledge or whether there are other forms, whether we are justified in considering it a superior type of knowledge, and if so, in what sense, whether there is any possibility of objectivity in knowledge, and whether a “hard science” is possible for human beings and their societies. These questions concern them and drive the progress of the philosophy of science.