Nothing is so dangerous to the progress of the human mind than to assume that our views of science are ultimate, that there are no mysteries in nature, that our triumphs are complete and that there are no new worlds to conquer.

We must reason in natural philosophy not from what we hope, or even expect, but from what we perceive.

The three states of the caterpillar, larva, and butterfly have, since the time of the Greek poets, been applied to typify the human being,--its terrestrial form, apparent death, and ultimate celestial destination.

The progression of physical science is much more connected with your prosperity than is usually imagined. You owe to experimental philosophy some of the most important and peculiar of your advantages. It is not by foreign conquests chiefly that you are become great, but by a conquest of nature in your own country.

Mr. Dalton's permanent reputation will rest upon his having discovered a simple principle, universally applicable to the facts of chemistry - in fixing the proportions in which bodies combine, and thus laying the foundation for future labors... his merits in this respect resemble those of Kepler in astronomy.

Geology, perhaps more than any other department of natural philosophy, is a science of contemplation. It requires no experience or complicated apparatus, no minute processes upon the unknown processes of matter. It demands only an enquiring mind and senses alive to the facts almost everywhere presented in nature. And as it may be acquired without much difficulty, so it may be improved without much painful exertion.

Cuvier had even in his address & manner the character of a superior Man, much general power & eloquence in conversation & great variety of information on scientific as well as popular subjects. I should say of him that he is the most distinguished man of talents I have ever known on the continent: but I doubt if He be entitled to the appellation of a Man of Genius.