In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.

The assumed instinctive belief in God has been used by many persons as an argument for his existence. But this is a rash argument, as we should thus be compelled to believe in the existence of many cruel and malignant spirits, only a little more powerful than man; for the belief in them is far more general than in a beneficent deity.

But when on shore, & wandering in the sublime forests, surrounded by views more gorgeous than even Claude ever imagined, I enjoy a delight which none but those who have experienced it can understand.

With mammals the male appears to win the female much more through the law of battle than through the display of his charms.

Our descent, then, is the origin of our evil passions!! The devil under form of Baboon is our grandfather.

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

The world will not be inherited by the strongest, it will be inherited by those most able to change.