Many politicians are in the habit of laying it down as a self-evident proposition that no people ought to be free till they are fit to use their freedom. The maxim is worthy of the fool in the old story who resolved not to go into the water till he had learned to swim

What proposition is there respecting human nature which is absolutely and universally true? We know of only one, – and that is not only true, but identical, – that men always act from self-interest

To be an outspoken professor in academia is a very dangerous proposition.

It is curious — the way the human mind works. The Christian begins with this straight proposition, this definite proposition, this inflexible and uncompromising proposition: God is allknowing, and all-powerful.

Every proposition which we can understand must be composed wholly of constituents with which we are acquainted.

But, you might say, “none of this shakes my belief that 2 and 2 are 4.” You are quite right, except in marginal cases—and it is only in marginal cases that you are doubtful whether a certain animal is a dog or a certain length is less than a meter. Two must be two of something, and the proposition “2 and 2 are 4” is useless unless it can be applied. Two dogs and two dogs are certainly four dogs, but cases arise in which you are doubtful whether two of them are dogs. “Well, at any rate there are four animals,” you may say. But there are microorganisms concerning which it is doubtful whether they are animals or plants. “Well, then living organisms,” you say. But there are things of which it is doubtful whether they are living organisms or not. You will be driven into saying: “Two entities and two entities are four entities.” When you have told me what you mean by “entity,” we will resume the argument.

At the age of eleven, I began Euclid, with my brother as my tutor. … I had not imagined that there was anything so delicious in the world. After I had learned the fifth proposition, my brother told me that it was generally considered difficult, but I had found no difficulty whatsoever. This was the first time it had dawned on me that I might have some intelligence.