I conclude that, while it is true that science cannot decide questions of value, that is because they cannot be intellectually decided at all, and lie outside the realm of truth and falsehood. Whatever knowledge is attainable, must be attained by scientific methods; and what science cannot discover, mankind cannot know.

The mind is a strange machine which can combine the materials offered to it in the most astonishing ways.

William James describes a man who got the experience from laughing-gas; whenever he was under its influence, he knew the secret of the universe, but when he came to, he had forgotten it. At last, with immense effort, he wrote down the secret before the vision had faded. When completely recovered, he rushed to see what he had written. It was 'A smell of petroleum prevails throughout'.

Advocates of capitalism are very apt to appeal to the sacred principles of liberty, which are embodied in one maxim: The fortunate must not be restrained in the exercise of tyranny over the unfortunate.

The puritanism of Christianity has played havoc with the moderation that an enlightened and tolerant critical spirit would have produced. I've noticed that in whatever country, county, town, or other region there is a regulation enjoining temperance, the population seems to be entirely composed of teetotallers and drunkards. There's a Bible on that shelf there. But I keep it next to Voltaire - poison and antidote.

Thinking you know when in fact you don't is a fatal mistake, to which we are all prone

As soon as we abandon our own reason, and are content to rely upon authority, there is no end to our troubles.