Consider the Koran... this wretched book was sufficient to start a world-religion, to satisfy the metaphysical need of countless millions for twelve hundred years, to become the basis of their morality and of a remarkable contempt for death, and also to inspire them to bloody wars and the most extensive conquests. In this book we find the saddest and poorest form of theism. Much may be lost in translation, but I have not been able to discover in it one single idea of value.

I am often surprised by the cleverness, and now and again by the stupidity, of my dog; and I have similar experiences with mankind.

There are, first of all, two kinds of authors: those who write for the subject's sake, and those who write for writing's sake.

Genius is an intellect that has become unfaithful to its destiny.

The man never feels the want of what it never occurs to him to ask for.

It is, indeed, only in old age that intellectual men attain their sublime expression, whilst portraits of them in their youth show only the first traces of it.

In our early youth we sit before the life that lies ahead of us like children sitting before the curtain in a theatre, in happy and tense anticipation of whatever is going to appear. Luckily we do not know what really will appear.