Farewell Australia! You ... are too great and ambitious for affection, yet not great enough for respect. I leave your shores without sorrow or regret.

I have deeply regretted that I did not proceed far enough at least to understand something of the great leading principles of mathematics, for men thus endowed seem to have an extra sense.

Man in his arrogance thinks himself a great work, worthy of the interposition of a deity. More humble, and I believe truer, to consider him created from animals.

Man in his arrogance thinks himself a great work.

Embryology will reveal to us the structure, in some degree obscured, of the prototypes of each great class.

The great variability of all the external differences between the races of man, likewise indicates that they cannot be of much importance; for if important, they would long ago have been either fixed and preserved, or eliminated.