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.

If a belief is not realized immediately in open deeds, it is stored up for the guidance of the future.

Our lives our guided by that general conception of the course of things which has been created by society for social purposes.

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.

He who truly believes that which prompts him to an action has looked upon the action to lust after it, he has committed it already in his heart.

Namely, we have no right to believe a thing true because everybody says so unless there are good grounds for believing that some one person at least has the means of knowing what is true, and is speaking the truth so far as he knows it.

No simplicity of mind, no obscurity of station, can escape the universal duty of questioning all that we believe.