What hunger is in relation to food, zest is in relation to life.

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.

Love and knowledge led upwards to the heavens.

Ever since men became capable of free speculation, their actions, in innumerable important respects, have depended upon their theories as to the world and human life, as to what is good and what is evil. This is true in the present day as at any former time. To understand an age or a nation, we must understand its philosophy, and to understand its philosophy we must ourselves be in some degree philosophers. There is here a reciprocal causation: the circumstances of men s lives do much to determine their philosophy, but, conversely, their philosophy does much to determine their circumstances.

There seems scarcely any limit to what could be done in the way of producing a good world, if only men would use science wisely.

You must believe that you can help bring about a better world. A good society is produced only by good individuals, just as truly as a majority in a presidential election is produced by the votes of single electors.

Really high-minded people are indifferent to happiness, especially other people's.