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.

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.

Religion is still parasitic in the interstices of our knowledge which have not yet been filled. Like bed-bugs in the cracks of walls and furniture, miracles lurk in the lacunae of science. The scientist plasters up these cracks in our knowledge; the more militant Rationalist swats the bugs in the open. Both have their proper sphere and they should realize that they are allies.

[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.

This is my prediction for the future: Whatever hasn't happened will happen, and no one will be safe from it.

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.