The trouble with having an open mind, of course, is that people will insist on coming along and trying to put things in it.

The way to deal with an impossible task was to chop it down into a number of merely very difficult tasks, and break each one of them into a group of horribly h…

Everything makes sense a bit at a time. But when you try to think of it all at once, it comes out wrong.

'You're not going to die, are you sir?' he said. 'Of course I am. Everyone is. That's what being alive is all about.'

Curiosity will conquer fear even more than bravery will.

Reason, or the ratio of all we have already known, is not the same that it shall be when we know more.

Knowledge is not a passion from without the mind, but an active exertion of the inward strength, vigour and power of the mind, displaying itself from within.