When we look at a rock what we are seeing is not the rock, but the effect of the rock upon us.

Philosophy arises from an unusually obstinate attempt to arrive at real knowledge. What passes for knowledge in ordinary life suffers from three defects: it is cocksure, vague and self-contradictory. The first step towards philosophy consists in becoming aware of these defects, not in order to rest content with a lazy scepticism, but in order to substitute an amended kind of knowledge which shall be tentative, precise and self-consistent.

The whole realm of thought and opinion is utterly unsuited to public control; it ought to be as free, and as spontaneous as is possible. The state is justified in insisting that children shall be educated, but it is not justified in forcing their education to proceed on a uniform plan and to be directed to the production of a dead level of glib uniformity.

But if thought is to become the possession of many, not the privilege of the few, we must have done with fear. It is fear that holds men back - fear lest their cherished beliefs should prove delusions, fear lest the institutions by which they live should prove harmful, fear lest they themselves should prove less worthy of respect than they have supposed themselves to be.

Man is a credulous animal, and must believe something; in the absence of good grounds for belief, he will be satisfied with bad ones.

A drop of water is not immortal; it can be resolved into oxygen and hydrogen. If, therefore, a drop of water were to maintain that it had a quality of aqueousness which would survive its dissolution we should be inclined to be skeptical. In like manner we know that the brain is not immortal.

This has been my life. I have found it worth living, and would gladly live it again if the second chance were offered me.