As man advances in civilization, and small tribes are united into larger communities, the simplest reason would tell each individual that he ought to extend his social instincts and sympathies to all members of the same nation, though personally unknown to him. This point being once reached, there is only an artificial barrier to prevent his sympathies extending to the men of all nations and races.

Great is the power of steady misrepresentation

... probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed.

Light will be thrown on the origin of man and his history.

Your words have come true with a vengeance that I shd [should] be forestalled ... I never saw a more striking coincidence. If Wallace had my M.S. sketch written out in 1842 he could not have made a better short abstract! Even his terms now stand as Heads of my Chapters.

If man had not been his own classifier, he would never have thought of founding a separate order for his own reception.

Man himself cannot express love and humility by external signs, so plainly as does a dog, when with drooping ears, hanging lips, flexuous body, and wagging tail, he meets his beloved master.