I am an absolute pacifist...It is an instinctive feeling. It is a feeling that possesses me, because the murder of men is disgusting.

My intellectual development was retarded, as a result of which I began to wonder about space and time only when I had already grown up.

In the past it never occurred to me that every casual remark of mine would be snatched up and recorded. Otherwise I would have crept further into my shell.

The opinion prevailed among advanced minds that it was time that belief should be replaced increasingly by knowledge; belief that did not itself rest on knowledge was superstition, and as such had to be opposed.

The future is of greater interest to me than the past, since that is where I intend to spend the rest of my life.

The fanatical atheists are like slaves who are still feeling the weight of their chains which they have thrown off after hard struggle. They are creatures who—in their grudge against traditional religion as the "opium of the masses"—cannot hear the music of the spheres.

Regarding sex education: no secrets!