The great poem and the deep theorem are new to every reader, and yet are his own experiences, because he himself recreates them.

When Da Vinci wanted an effect, he willed, he planned the means to make it happen: that was the purpose of his machines. But the machines of Newton ... are means not for doing but for observing. He saw an effect, and he looked for its cause.

Many theories of the ancient world seem terribly childish today, a hodge-podge of fables and false comparisons.But our theories will seem childish five-hundred years from now.Every theory is based on some analogy, and sooner or later the theory fails because the analogy turns out to be false. A theory in its day helps to solve the problems of the day.

The private motives of scientists are not the trend of science. The trend of science is made by the needs of society: navigation before the eighteenth century, manufacture thereafter; and in our age I believe the liberation of personality. Whatever the part which scientists like to act, or for that matter which painters like to dress, science shares the aims of our society just as art does.

It is a mistake to think of creative activity as something unusual

Satire is not a social dynamite. But it is a social indicator: it shows that new men are knocking at the door.

The world is made up of people who never quite get into the first team and who just miss the prizes at the flower show.