The tree of life should perhaps be called the coral of life, base of branches dead; so that passages cannot be seen-this again offers contradiction to constant succession of germs in progress.

What wretched doings come from the ardor of fame; the love of truth alone would never make one man attack another bitterly.

The moral faculties are generally esteemed, and with justice, as of higher value than the intellectual powers. But we should always bear in mind that the activity of the mind in vividly recalling past impressions is one of the fundamental though secondary bases of conscience. This fact affords the strongest argument for educating and stimulating in all possible ways the intellectual faculties of every human being.

The willing horse is always overworked.

There is no fundamental difference between man and the higher mammals in their mental faculties...The difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind.

Animals manifestly enjoy excitement, and suffer from annul and may exhibit curiosity.

Nevertheless so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world, or invent laws on the duration of the forms of life!