Bertrand Russell - The Problems of Philosophy

Philosophy is to be studied, not for the sake of any definite answers to its questions, since no definite answers can, as a rule, be known to be true, but rather for the sake of the questions themselves; because these questions enlarge our conception of what is possible, enrich our intellectual imagination and diminish the dogmatic assurance which closes the mind against speculation; but above all because, through the greatness of the universe which philosophy contemplates, the mind is also rendered great, and becomes capable of that union with the universe which constitutes its highest good.

Robert Klee (editor) - Scientific Inquiry: Readings in the Philosophy of Science

The totality of our so-called knowledge or beliefs, from the most casual matters of geography and history to the profoundest laws of atomic physics or even of pure mathematics and logic, is a man-made fabric which impinges on experience only along the edges. -- W.V. Quine

John Losee - A Historical Introduction to the Philosophy of Science (1st Edition:1972)

The distinction which has been indicated between science and philosophy of science is not a sharp one. It is based on a difference of intent rather than a difference in subject-matter.