Linnaeus and Cuvier have been my two gods, though in very different ways, but they were mere schoolboys to old Aristotle.

Building a better mousetrap merely results in smarter mice.

Among the scenes which are deeply impressed on my mind, none exceed in sublimity the primeval [tropical] forests, ... temples filled with the varied productions of the God of Nature. No one can stand in these solitudes unmoved, and not feel that there is more in man than the mere breath of his body.

...I have always maintained that, excepting fools, men did not differ much in intellect, only in zeal and hard work; and I still think there is an eminently important difference.

If I had life to live over again, I would give my life to poetry, to music, to literature, and to art to make life richer and happier. In my youth I steeled myself against them and thought them so much waste.

It is not the biggest, the brightest or the best that will survive, but those who adapt the quickest.

... not one living species will transmit its unaltered likeness to a distant futurity.