In art, truth is a means to an end; in science, it is the only end.

There is a mask of theory over the whole face of nature.

Nobody since Newton has been able to use geometrical methods to the same extent for the like purposes; and as we read the Principia we feel as when we are in an ancient armoury where the weapons are of gigantic size; and as we look at them we marvel what manner of man he was who could use as a weapon what we can scarcely lift as a burden.

We cannot observe external things without some degree of Thought; nor can we reflect upon our Thoughts, without being influenced in the course of our reflection by the Things which we have observed.

It is a test of true theories not only to account for but to predict phenomena.

To discover the laws of operative power in material productions, whether formed by man or brought into being by Nature herself, is the work of a science, and is indeed what we more especially term Science.

Every failure is a step to success. Every detection of what is false directs us towards what is true: every trial exhausts some tempting form of error.