Sympathy for the lowest animals is one of the noblest virtues with which man is endowed.

Mathematics seems to endow one with something like a new sense.

How so many absurd rules of conduct, as well as so many absurd religious beliefs, have originated, we do not know; nor how it is that they have become, in all quarters of the world, so deeply impressed on the minds of men; but it is worthy of remark that a belief constantly inculcated during the early years of life, while the brain is impressionable, appears to acquire almost the nature of an instinct; and the very essence of an instinct is that it is followed independently of reason.

It is always advisable to perceive clearly our ignorance.

It is mere rubbish thinking, at present, of origin of life; one might as well think of origin of matter.

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

There is no fundamental difference between humans and the higher mammalsin their mental faculties