Shelley and Keats were the last English poets who were at all up to date in their chemical knowledge.

There are 400,000 species of beetles on this planet, but only 8,000 species of mammals.

Every Christian church has tried to impose a code of morals of some kind for which it has claimed divine sanction. As these codes have always been opposed to those of the gospels a loophole has been left for moral progress such as hardly exists in other religions.

[Children] are taught that it is a virtue to accept statements without adequate evidence, which leaves them a prey to quacks of every kind in later life, and makes it very difficult for them to accept the methods of thought which are successful in science.

Reality is the cage of those who lack imagination.

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.

We must learn not to take traditional morals too seriously. And it is just because even the least dogmatic of religions tends to associate itself with some kind of unalterable moral tradition, that there can be no truce between science and religion.