The novel, in its best form, I regard as one of the most powerful engines of civilization ever invented.

Speculations apparently the most unprofitable have almost invariably been those from which the greatest practical applications have emanated.

It can hardly be pressed forcibly enough on the attention of the student of nature, that there is scarcely any natural phenomenon which can be fully and completely explained, in all its circumstances, without a union of several, perhaps of all, the sciences.

The barrier has begun to yield.

Every student who enters upon a scientific pursuit, especially if at a somewhat advanced period of life, will find not only that he has much to learn, but much also to unlearn.

...Nature builds up her refined and invisible architecture, with a delicacy eluding our conception, yet with a symmetry and beauty which we are never weary of admiring.

The besetting evil of our age is the temptation to squander and dilute thought on a thousand different lines of inquiry.