Science tells us what we can know but what we can know is little and if we forget how much we cannot know we become insensitive of many things of very great importance. Theology, on the other hand induces a dogmatic belief that we have knowledge where in fact we have ignorance and by doing so generates a kind of impertinent insolence towards the universe. Uncertainty in the presence of vivid hopes and fears is painful, but must be endured if we wish to live without the support of comforting fairy tales.

The true function of logic ... as applied to matters of experience ... is analytic rather than constructive; taken a priori, it shows the possibility of hitherto unsuspected alternatives more often than the impossibility of alternatives which seemed prima facie possible. Thus, while it liberates imagination as to what the world may be, it refuses to legislate as to what the world is

He will see himself and life and the world as truly as our human limitations will permit; realizing the brevity and minuteness of human life, he will realize also that in individual minds is concentrated whatever of value the known universe contains. And he will see that the man whose mind mirrors the world becomes in a sense as great as the world. In emancipation from the fears that beset the slave of circumstance he will experience a profound joy, and through all the vicissitudes of his outward life he will remain in the depths of his being a happy man.

Everything is vague to a degree you do not realize till you have tried to make it precise.

Citizens as conceived by governments are persons who admire the status quo and are prepared to exert themselves for its preservation. Oddly enough, while all governments aim at producing men of this type to the exclusion of all other types, their heroes in the past are of exactly the sort that they aim at preventing in the present. Americans admire George Washington and Jefferson, but imprison those who share their political opinions.

Descartes, the father of modern philosophy ... would never-so he assures us-have been led to construct his philosophy if he had had only one teacher, for then he would have believed what he had been told; but, finding that his professors disagreed with each other, he was forced to conclude that no existing doctrine was certain.

Most of the greatest evils that man has inflicted upon man have come through people feeling quite certain about something which, in fact, was false.