Jean-Paul Sartre - Existentialism Is a Humanism

Man is not only that which he conceives himself to be, but that which he wills himself to be, and since he conceives of himself only after being thrown into existence, man is nothing other than what he makes of himself.

Jerry H. Gill - Metaphilosophy: An Introduction

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.

James Bissett Pratt - Naturalism

Its (naturalism) aim, as we have seen, is not propaganda; neither is it self-deception. It is seeking not a pleasant feeling state nor a comfortable belief, but the truth. And Naturalism believes that the truth is what it is, no matter what we think about it. Nature, the world of reality, has a character, a structure of its own, and our opinions are true only in so far as they conform to this actual situation. (...) Another form of the Will-to-Believe which the naturalist cannot share is the attitude of the man who, more or less deliberately, allows his view of Reality to be colored or determined by the romantic and poetic tendencies of the human mind. This does not mean that the naturalistic view will necessarily be unpoetic or ugly. That will be as it will be. But the influences which, in the last analysis, determine the naturalistic Weltanschauung are not the appeal of the beautiful or the pathetic, the tragic or the pleasing, but unprejudiced reason and empirical observation. The naturalist may or may not be a poet: but while he is investigating the nature of Reality he is bound to be a realist. He may be fond of poetry and he will be fond of knowledge.

Josef Pieper - Leisure, The Basis of Culture

Leisure cannot be realized so long as one understands it to be a means, even as a means to the end of "rescuing the culture of Christian Europe." The celebration of God's praises cannot be realized unless it takes place for its own sake.