In scientific work, those who refuse to go beyond fact rarely get as far as fact.

That which endures is not one or another association of living forms, but the process of which the cosmos is the product, and of which these are among the transitory expressions.

The secret of genius is to carry the spirit of childhood into maturity.

I have never been able to understand why pigeon-shooting at Hurlingham should be refined and polite, while a rat-killing match in Whitechapel is low.

A world of facts lies outside and beyond the world of words.

The rules of the game are what we call the laws of nature.

As for your doctrines I am prepared to go to the Stake if requisite ... I trust you will not allow yourself to be in any way disgusted or annoyed by the considerable abuse & misrepresentation which unless I greatly mistake is in store for you... And as to the curs which will bark and yelp - you must recollect that some of your friends at any rate are endowed with an amount of combativeness which (though you have often & justly rebuked it) may stand you in good stead - I am sharpening up my claws and beak in readiness.