The instruction at Edinburgh was altogether by lectures, and these were intolerably dull, with the exception of those on chemistry.

Even the humblest mammal's strong sexual, parental, and social instincts give rise to 'do unto others as yourself' and 'love thy neighbor as thyself'.

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

Great is the power of steady misrepresentation; but the history of science shows that fortunately this power does not long endure.

I am not the least afraid to die

Ignorance more frequently begets confidence than does knowledge.

Traveling ought also to teach him distrust; but at the same time he will discover, how many truly kind-hearted people there are, with whom he never before had, or ever again will have any further communication, who yet are ready to offer him the most disinterested assistance.