In all sensation we pick and choose, interpret, seek and impose order, and devise and test hypotheses about what we witness. Sense data are taken, not merely given: we learn to perceive.... The teacher has forgotten, and the student himself will soon forget, that what he sees conveys no information until he knows beforehand the kind of thing he is expected to see.

[A certain class of explanations in science are] analgesics that dull the ache of incomprehension without removing the cause.

French is not a language that lends itself naturally to the opaque and ponderous idiom of nature-philosophy, and Teilhard has according resorted to the use of that tipsy, euphoristic prose-poetry which is one of the more tiresome manifestations of the French spirit.

The alternative to thinking in evolutionary terms is not to think at all.

I cannot give any scientist of any age better advice than this: the intensity of a conviction that a hypothesis is true has no bearing over whether it is true or not.

Ask a scientist what he conceives the scientific method to be and he will adopt an expression that is at once solemn and shifty-eyed: solemn, because he feels he ought to declare an opinion; shifty-eyed, because he is wondering how to conceal the fact that he has no opinion to declare.

Today the world changes so quickly that in growing up we take leave not just of youth but of the world we were young in.