You cannot love the girl without being conscious of the fact that she has yellow hair, you cannot see the world without the intervention of the physi… - Jacob Bronowski

Though I dwelt with that heathen of the heathen, Laban, yet have I not forgotten my God, but I fulfil the six hundred and thirteen commandments of the Torah. If thy mind be set upon peace, thou wilt find me ready for peace. But if thy desire be war, thou wilt find me ready for war. I have with me men of valor and strength, they have but to utter a word, and God fulfils it. I tarried with Laban until Joseph should be born, he who is destined to subdue thee. And though my descendants be held in bondage in this world, yet a day will come when they will rule over their rulers.

The genius of men like Newton and Einstein lies in that: they ask transparent, innocent questions which turn out to have catastrophic answers. The poet William Cowper called Newton a ‘childlike sage’ for that quality, and the description perfectly hits the air of surprise at the world that Einstein carried in his face. Whether he talked about riding a beam of light or falling through space, Einstein was always full of beautiful, simple illustrations of such principles, and I shall take a leaf out of his book. I go to the bottom of the clocktower, and get into the tram he used to take every day on his way to work as a clerk in the Swiss Patent Office.

The Principle of Uncertainty is a bad name. In science, or outside of it, we are not uncertain; our knowledge is merely confined, within a certain tolerance. We should call it the Principle of Tolerance. And I propose that name in two senses. First, in the engineering sense: Science has progressed, step by step, the most successful enterprise in the ascent of man, because it has understood that the exchange of information between man and nature, and man and man, can only take place with a certain tolerance. But second, I also use the word, passionately, about the real world. All knowledge – all information between human beings – can only be exchanged within a play of tolerance. And that is true whether the exchange is in science, or in literature, or in religion, or in politics, or in any form of thought that aspires to dogma. It's a major tragedy of my lifetime and yours that scientists were refining, to the most exquisite precision, the Principle of Tolerance – and turning their backs on the fact that all around them, tolerance was crashing to the ground beyond repair. The Principle of Uncertainty or, in my phrase, the Principle of Tolerance, fixed once for all the realization that all knowledge is limited. It is an irony of history that at the very time when this was being worked out, there should rise, under Hitler in Germany and other tyrants elsewhere, a counter-conception: a principle of monstrous certainty. When the future looks back on the 1930's, it will think of them as a crucial confrontation of culture as I have been expounding it – the ascent of man against the throwback to the despots' belief that they have absolute certainty.