In the struggle for survival, the fittest win out at the expense of their rivals because they succeed in adapting themselves best to their environment.

Nothing before had ever made me thoroughly realise, though I had read various scientific books, that science consists in grouping facts so that general laws or conclusions may be drawn from them.

Sympathy will have been increased through natural selection

Each organic being is striving to increase in a geometrical ratio . . . each at some period of its life, during some season of the year, during each generation or at intervals, has to struggle for life and to suffer great destruction . . . The vigorous, the healthy, and the happy survive and multiply.

If I had not been so great an invalid, I should not have done so much as I have accomplished.

Many kinds of monkeys have a strong taste for tea, coffee and spirituous liqueurs.

The western nations of Europe, who now so immeasurably surpass their former savage progenitors, and stand at the summit of civilization, owe little or none of their superiority to direct inheritance from the old Greeks, though they owe much to the written works of that wonderful people.