It is for this reason that rationality is of supreme importance to the well-being of the human species...even more, in those less fortunate times in which it is despised and rejected as the vain dream of men who lack the virility to kill where they cannot agree.

Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true.

The desire to understand the world and the desire to reform it are the two great engines of progress, without which human society would stand still or retrogress.

All human activity is prompted by desire.

In human relations one should penetrate to the core of loneliness in each person and speak to that.

One of the most interesting and harmful delusions to which men and nations can be subjected is that of imagining themselves special instruments of the Divine Will.

We may say, in a broad way, that Greek philosophy down to Aristotle expresses the mentality appropriate to the City State; that Stoicism is appropriate to a cosmopolitan despotism; that stochastic philosophy is an intellectual expression of the Church as an organization; that philosophy since Descartes, or at any rate since Locke, tends to embody the prejudices of the commercial middle class; and that Marxism and Fascism are the philosophies appropriate to the modern industrial state.