Mathematics takes us into the region of absolute necessity, to which not only the actual word, but every possible word, must conform.

It is only theory that makes men completely incautious.

The pure mathematician, like the musician, is a free creator of his world of ordered beauty.

What is best in mathematics deserves not merely to be learnt as a task, but to assimilated as a part of daily thought, and brought again and again before the mind with ever-renewed encouragement.

Drunkenness is temporary suicide.

Why repeat the old errors, if there are so many new errors to commit?

The Christian view that all intercourse outside marriage is immoral was, as we see in the above passages from St. Paul, based upon the view that all sexual intercourse, even within marriage, is regrettable. A view of this sort, which goes against biological facts, can only be regarded by sane people as a morbid aberration. The fact that it is embedded in Christian ethics has made Christianity throughout its whole history a force tending towards mental disorders and unwholesome views of life.