Without deductive logic science would be entirely useless. It is merely a barren game to ascend from the particular to the general, unless afterwards we can reverse the process and descend from the general to the particular, ascending and descending like angels on Jacob's ladder.

The point of mathematics is that in it we have always got rid of the particular instance, and even of any particular sorts of entities. So that for example, no mathematical truths apply merely to fish, or merely to stones, or merely to colours. So long as you are dealing with pure mathematics, you are in the realm of complete and absolute abstraction. . . . Mathematics is thought moving in the sphere of complete abstraction from any particular instance of what it is talking about.

The absolute pacifist is a bad citizen; times come when force must be used to uphold right, justice and ideals.

I consider Christianity to be one of the great disasters of the human race... It would be impossible to imagine anything more un - Christianlike than theology.

Everything of importance has been said before by somebody who did not discover it.

Our reasonings grasp at straws for premises and float on gossamers for deductions.

Education with inert ideas is not only useless; it is above all things harmful.