When the Greeks invented science and mathematics in around 600 BC, it was considered as a part of philosophy. Thales of Miletus was a mathematician and philosopher. Aristotle was a philosopher, biologist and physicist. Eratosthenes was a earth scientist, mathematician and philosopher. There are of course many more examples.

Nowadays, physics, chemistry, mathematics, biology, earth science are all separated from philosophy. However, ethics, philosophical anthropology, epistemology and metaphysics are part of philosophy.

Two questions:

  • Why and when did physics, chemistry, mathematics and earth science merit an own field?
  • Why don't ethics and metaphysics merit an own field?

I think that it certainly has to do something with size, since the former fields grew a lot in the 16th century. But the latter fields already were very large, since they were studied a lot more in ancient Greek times.


3 Answers 3


The area of knowledge separates itself from philosophy as soon as a reliable method of obtaining exact knowledge in this area is invented. Thus mathematics separated from philosophy at its very beginning. In astronomy, there was an area covered by exact knowledge (based on observations) and another, speculative part. As exact knowledge expanded, the speculative part shrinked. Ancient Greek work in statics is exact knowledge. Dynamics remained a part of philosophy until Galileo and Newton. Newton's title "Mathematical principles of natural philosophy" signifies the transition point. Since this book, most of physics is not philosophy anymore. (Though the name "natural philosophy" existed for another 200 years, and even now a degree in mathematics is called PhD in some countries).

The last part of astronomy which separated from philosophy was cosmology.

In areas like ethics, aesthetics, metaphysics, theology, etc., a method of obtaining exact, objective knowledge still does not exist. So they remain parts of philosophy.

It is true, Thales was both a mathematician and a philosopher. Pascal, Descartes, Leibniz and even Cantor, Russell and Thom did philosophy as well. But their mathematical work is very clearly separated from philosophy.

  • 1
    $\begingroup$ I would ague that "Philosophical Diploma" (PhD) remains a valid word to use for every scientific discipline, since "Philosophy" in (ancient) Greek literally means "friend of knowledge/wisdom". $\endgroup$ Jul 31, 2015 at 0:24
  • $\begingroup$ @Alecos Papadopulos: "PhD" does not stand for "Philosophical Diploma" but for "Doctor of Philosophy". $\endgroup$ Aug 1, 2015 at 2:58
  • 1
    $\begingroup$ Certainly, I always forget the underlying Latin structure of the abbreviation. Still, the interpretation is exactly the same. $\endgroup$ Aug 1, 2015 at 3:30

I often say the following, especially to philosophers.

Philosophy is the study of problems which cannot be solved.
As soon as a problem can be solved, it moves to the science faculty.

But one philosopher told me that at least in ethics, philosophers (i.e. philosophers in the academic/university system) do solve problems. Well, I can't agree with that. Ethics is the study of what should be. Science is the study of what is. So ethics can never be a science. One can, however, systematize ethics in terms of an axiomatic system or various rule-based systems. But just because something looks very technical doesn't mean it's a science. (Take astrology for example!)

Historically, many subjects were actually a part of religion, not philosophy. As more has become known about geology, biology, medicine, cosmology and psychology, these subjects have moved to the science faculty. People used to give gifts to the god Asclepius to cure diseases, and they gave gifts to the gods of harvests to get a successful crop. Now people give their gifts to doctors and seed and fertilizer companies.

So to answer the question, some subjects never acquired objective means of obtaining knowledge.

I think also that many areas of philosophy are actually conducted within each field, like philosophy of mathematics, philosophy of physics, and so forth. It's a bit like mathematics because mathematics is a tool which is applied to dozens of subjects. Philosophy can also be regarded as a method, which can be applied to any subject. So every subject has its own philosophy now. The philosophy department of a university focuses mainly on applications of philosophical thinking to problems that are either not related to the real world, or are just not amenable to objective methods yet, like: "What is the nature of consciousness and awareness?"

  • 2
    $\begingroup$ I would like to see a specific problem in ethics which is SOLVED. And the solution. $\endgroup$ Aug 1, 2015 at 3:01
  • 1
    $\begingroup$ @Alexandre Eremenko In my opinion, the path from ignorance to science goes through 3 phases. Some subjects don't get past the first phase. Phase 1 is description (observation, naming and classification). Phase 2 is prediction, where you test theories by experiment. Phase 3 is engineering, where you specify what you want to happen in the future, and you make it happen by designing systems using phase 2 knowledge. Well, ethics just gets to phase 1. In fact, ethics never even pretends to be a form of knowledge. It's just a system of values and rules for behavior. It will never get to phase 2! $\endgroup$ Aug 1, 2015 at 4:00
  • $\begingroup$ By the way, I have often thought that ethics should move to the anthropology department. The only reason it does not, in my opinion, is that this would imply "cultural relativism", whereas many people want to claim that ethics is somehow absolute, like a science. So ethics is something which could separate itself from philosophy, but philosophers have considered ethics to be their territory since Socrates. Even in physics, the philosophers do not want to let go of their territory. They continue to philosophize about physics. E.g. the books by Kuhn and Popper, and later related works. $\endgroup$ Aug 1, 2015 at 4:36
  • 1
    $\begingroup$ One can pholosophize about everything,, including physics and mathematics, as long as you discuss questions which cannot be solved with exact methods. But in all cases when philosophers intrude in the area which belongs to an exact science, they loose. Recent examples include intrusion of "Marxist philosophy" to physics and biology. $\endgroup$ Aug 1, 2015 at 12:41

As a second answer to the main question, I just remembered that logic is an "outlier" as a subject which used to lie inside the philosophy department because of Aristotle's "Logic" book. (Philosophy used to cover all of the topics written about by Aristotle and Plato.) But then logic moved into mathematics, more or less, from about 1890 up to about 1965, because it was introduced into mathematics by Peano, a mathematician, in the late 19th century with his 1899 "Arithmetices principia: Nova methodo exposita", which included an axiomatization of logic (and set/class theory) written entirely in Latin. This was then followed by the Whitehead/Russell 1910, 1912, 1913 "Principia mathematica", which also axiomatized logic. There were many other logic axiomatizations, which sort of moved between the philosophy and mathematics departments. However, after Paul Cohen's solution of the problem of the independence of the axiom of choice (and the continuum hypothesis) relative to Zermelo-Fraenkel set theory, logic seems to have moved back into the philosophy departments again.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.