No satisfaction based upon self-deception is solid.

To create a healthy philosophy you should renounce metaphysics but be a good mathematician.

Passive acceptance of the teacher's wisdom is easy to most boys and girls. It involves no effort of independent thought, and seems rational because the teacher knows more than his pupils; it is moreover the way to win the favour of the teacher unless he is a very exceptional man. Yet the habit of passive acceptance is a disastrous one in later life. It causes man to seek and to accept a leader, and to accept as a leader whoever is established in that position.

Whether science-and indeed civilization in general-can long survive depends upon psychology, that is to say, it depends upon what human beings desire.

The scientific attitude of mind involves a sweeping away of all other desires in the interests of the desire to know-it involves suppression of hopes and fears, loves and hates, and the whole subjective emotional life, until we become subdued to the material, able to see it frankly, without preconceptions, without bias, without any wish except to see it as it is, and without any belief that what it is must be determined by some relation, positive or negative, to what we should like it to be, or to what we can easily imagine it to be.

The essence of the liberal outlook lies not in what opinions are held, but in how they are held; instead of being held dogmatically, they are held tentatively, and with a consciousness that new evidence may at any moment lead to their abandonment.

Any philosophy worth taking seriously would have to be built upon a firm foundation of unyielding despair.