The lowest strata are reproducing too fast. Therefore... they must not have too easy access to relief or hospital treatment lest the removal of the last check on natural selection should make it too easy for children to be produced or to survive; long unemployment should be a ground for sterilisation.

Evolution... is the most powerful and the most comprehensive idea that has ever arisen on Earth.

This earth is one of the rare spots in the cosmos where mind has flowered. Man is a product of nearly three billion years of evolution, in whose person the evolutionary process has at last become conscious of itself and its possibilities. Whether he likes it or not, he is responsible for the whole further evolution of our planet.

We all know how the size of sums of money appears to vary in a remarkable way according as they are being paid in or paid out.

Quantity of material production can only be a means to a further end, not an end in itself.

The proof given by Wright, that non-adaptive differentiation will occur in small populations owing to "drift," or the chance fixation of some new mutation or recombination, is one of the most important results of mathematical analysis applied to the facts of neo-mendelism. It gives accident as well as adaptation a place in evolution, and at one stroke explains many facts which puzzled earlier selectionists, notably the much greater degree of divergence shown by island than mainland forms, by forms in isolated lakes than in continuous river-systems.

Some day no one will have to work more than two days a week... The human being can consume so much and no more. When we reach the point when the world produces all the goods that it needs in two days, as it inevitably will, we must curtail our production of goods and turn our attention to the great problem of what to do with our new leisure.