Inductive inference is the only process known to us by which essentially new knowledge comes into the world.

The best time to plan an experiment is after you've done it.

To consult the statistician after an experiment is finished is often merely to ask him to conduct a post mortem examination. He can perhaps say what the experiment died of.

The tendency of modern scientific teaching is to neglect the great books, to lay far too much stress upon relatively unimportant modern work, and to present masses of detail of doubtful truth and questionable weight in such a way as to obscure principles.

Natural selection is a mechanism for generating an exceedingly high degree of improbability.

We can set no limit to human potentialities; all that is best in man can be bettered; it is not a question of producing a highly efficient machine, ... but of quickening all the distinctly human features, all that is best in man, all the different qualities, some obvious, some infinitely subtle, which we recognize as humanly excellent.

The best causes tend to attract to their support the worst arguments, which seems to be equally true in the intellectual and in the moral sense.