scientific thought does not mean thought about scientific subjects with long names. There are no scientific subjects. The subject of science is the human universe; that is to say, everything that is, or has been, or may be related to man.

The scientific discovery appears first as the hypothesis of an analogy; and science tends to become independent of the hypothesis.

The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous, and lose the habit of testing things and inquiring into them; for then it must sink back into savagery.

We may always depend on it that algebra, which cannot be translated into good English and sound common sense, is bad algebra.

Remember that [scientific thought] is the guide of action; that the truth which it arrives at is not that which we can ideally contemplate without error, but that which we may act upon without fear; and you cannot fail to see that scientific thought is not an accompaniment or condition of human progress, but human progress itself.

There is one thing in the world more wicked than the desire to command, and that is the will to obey.

To know all about anything is to know how to deal with it under all circumstances.