"Philosophy" is a word which has been used in many ways, sowe wider, some narrower. I propose to use it in a very wide sense, which I will soon try to explain.
Philosophy, as I shall understand the word, is something intermediate between theology and science. Like theology, it consists of speculations on matters as to which definite knowledge has, so far, been unascertainable; but like science, it appeals to human reason rather than to authority, whether that of tradition or that of revelation. All definite knowledge - so I should contend - belongs to science; all dogma as to what surpasses definite knowledge belongs to theology. But between theology and science there is a No Man's Land, exposed to attacks from both sides; this No Man's Land is philosophy.
In other words, philosophy is the left-overs of rational thought, that can't (yet) be tackled by science. Do you agree or not?
Historically, there is much merit to this description. Many fields that were once philosophical are now scientific. Currently, I think philosophy of mind is making progress into becoming a scientific field. However, I have a hard time seeing philosophy of science and epistemology ever becoming sciences.