The child who has been taught to make an accurate elevation, plan, and section of a pint pot has had an admirable training in accuracy of eye and hand.

Time, whose tooth gnaws away everything else, is powerless against truth.

Science is nothing but trained and organized common sense differing from the latter only as a veteran may differ from a raw recruit: and its methods differ from those of common sense only as far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.

I doubt the fact, to begin with, but if it be so even, what is this but in grand words asking me to believe a thing because I like it.

The doctrine of transmigration… was a means of constructing a plausible vindication of the ways of the cosmos to man; … none but very hasty thinkers will reject it on the grounds of inherent absurdity.

... our "Physick" and "Anatomy" have embraced such infinite varieties of being, have laid open such new worlds in time and space, have grappled, not unsuccessfully, with such complex problems, that the eyes of Vesalius and of Harvey might be dazzled by the sight of the tree that has grown out of their grain of mustard seed.

Not only does every animal live at the expense of some other animal or plant, but the very plants are at war.... The individuals of a species are like the crew of a foundered ship, and none but good swimmers have a chance of reaching the land.