So-called professional mathematicians have, in their reliance on the relative incapacity of the rest of mankind, acquired for themselves a reputation for profundity very similar to the reputation for sanctity possessed by theologians.

A vacuum of ideas affects people differently than a vacuum of air, otherwise readers of books would be constantly collapsing.

There is something in our minds like sunshine and the weather, which is not under our control. When I write, the best things come to me from I know not where.

The highest point to which a weak but experienced mind can rise is detecting the weakness of better men.

A book is a mirror: if an ape looks into it an apostle is hardly likely to look out.

Do not say hypothesis, and even less theory: say way of thinking.

The writer who cannot sometimes throw away a thought about which another man would have written dissertations, without worry whether or not the reader will find it, will never become a great writer.