We have two kinds of morality side by side: one which we preach but do not practice and another which we practice but seldom preach. – Bertrand Russell
The observer, when he seems to himself to be observing a stone, is really, if physics is to be believed, observing the effects of the stone upon himself. – Bertrand Russell
The theoretical understanding of the world, which is the aim of philosophy, is not a matter of great practical importance to animals, or to savages, or even to most civilised men. – Bertrand Russell
Aristotle could have avoided the mistake of thinking that women have fewer teeth than men, by the simple device of asking Mrs. Aristotle to keep her mouth open while he counted. – Bertrand Russell