Knowledge is not a loose-leaf notebook of facts. Above all, it is a responsibility for the integrity of what we are, primarily of what we are as ethical creatures.

Dissent is the native activity of the scientist, and it has got him into a good deal of trouble in the last years. But if that is cut off, what is left will not be a scientist. And I doubt whether it will be a man.

[John] Dalton was a man of regular habits. For fifty-seven years he walked out of Manchester every day; he measured the rainfall, the temperature-a singularly monotonous enterprise in this climate. Of all that mass of data, nothing whatever came. But of the one searching, almost childlike question about the weights that enter the construction of these simple molecules-out of that came modern atomic theory. That is the essence of science: ask an impertinent question, and you are on the way to the pertinent answer.

The central opposition between magic and science is the opposition between power and knowledge.

Man is a singular creature. He has a set of gifts which make him unique among the animals, so that unlike them, he is not a figure in the landscape, he is the shaper of the landscape.

Science, like art, is not a copy of nature but a re-creation of her.

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.