After five years' work I allowed myself to speculate on the subject, and drew up some short notes; these I enlarged in 1844 into a sketch of the conclusions, which then seemed to me probable: from that period to the present day I have steadily pursued the same object. I hope that I may be excused for entering on these personal details, as I give them to show that I have not been hasty in coming to a decision.‎

Natural selection acts solely by accumulating slight successive favorable variations, it can produce no great or sudden modification; it can act only by very short steps.

Such simple instincts as bees making a beehive could be sufficient to overthrow my whole theory.

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

In my simplicity, I remember wondering why every gentleman did not become an ornithologist.

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

It at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed.