Until politics are a branch of science, we shall do well to regard political and social reforms as experiments rather than short-cuts to the millennium.

A discussion between Haldane and a friend began to take a predictable turn. The friend said with a sigh, 'It's no use going on. I know what you will say next, and I know what you will do next.' The distinguished scientist promptly sat down on the floor, turned two back somersaults, and returned to his seat. 'There,' he said with a smile. 'That's to prove that you're not always right.'

A time will however come (as I believe) when physiology will invade and destroy mathematical physics, as the latter has destroyed geometry.

Quantitative work shows clearly that natural selection is a reality, and that, among other things, it selects Mendelian genes, which are known to be distributed at random through wild populations, and to follow the laws of chance in their distribution to offspring. In other words, they are an agency producing variation of the kind which Darwin postulated as the raw material on which selection acts.

The conservative has but little to fear from the man whose reason is the servant of his passions, but let him beware of him in whom reason has become the greatest and most terrible of the passions. These are the wreckers of outworn empires and civilisations, doubters, disintegrators, deicides.

It was a reaction from the old idea of "protoplasm", a name which was a mere repository of ignorance.

In fact, words are well adapted for description and the arousing of emotion, but for many kinds of precise thought other symbols are much better.