A mathematician is a blind man in a dark room looking for a black cat which isn't there.

I trust and believe that the time spent in this voyage ... will produce its full worth in Natural History; and it appears to me the doing what little we can to increase the general stock of knowledge is as respectable an object of life, as one can in any likelihood pursue.

The traveler may feel assured, he will meet with no difficulties or dangers, excepting in rare cases, nearly so bad as he beforehand anticipates. In a moral point of view, the effect ought to be, to teach him good-humored patience, freedom from selfishness, the habit of acting for himself, and of making the best of every occurrence.

We are not here concerned with hopes or fears, only with truth as far as our reason permits us to discover it.

Great is the power of steady misrepresentation

Nothing can be more improving to a young naturalist, than a journey in a distant country.

Free will is to mind what chance is to matter.