Charles DARWIN, 1871: Descent of Man, Great Books of the Western World Vol. 49, 1952, Encyclopaedia Britannica.

Looking to future generations, there is no cause to fear that the social instincts will grow weaker, and we may expect that virtuous habits will grow stronger, becoming perhaps fixed by inheritance. In this case the struggle between our higher and lower impulses will be less severe, and virtue will be triumphant. [Chapter 4, p. 319.]

These [intellectual and moral] faculties are variable; and we have every reason to believe that the variations tend to be inherited. Therefore, if they were formerly of high importance to primeval man and to his ape-like progenitors, they would have been perfected or through natural selection. [Chapter 5, p. 320.]

A tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good, would be victorious over most other tribes; and this would be natural selection. [Chapter 5, p. 322.]

It is, however, very difficult to form any judgment why one particular tribe and not another has been successful and has risen in the scale of civilization. Many savages are in the same condition as when first discovered several centuries ago. ... We are apt to look at the progress as normal in human society; but history refutes this. ... Progress seems to depend on many concurrent favourable conditions, far too complex to be followed out. [Chapter 5, p. 323.]

Great lawgivers, the founders of beneficent religions, great philosophers and discoverers in science, aid the progress of mankind in a far higher degree by their works than by leaving a numerous progeny. [Chapter 5, p. 323.]

With civilised nations, ..., natural selection apparently effects but little. [Chapter 5, p. 323.]

It is very difficult to say why one civilised nation rises, becomes more powerful, and spreads more widely, than another; ... Natural selection acts only tentatively. [Chapter 5, p. 327.]