“Aestheticism and radicalism must lead us to jettison reason, and to replace it by a desperate hope for political miracles. This irrational attitude which springs from intoxication with dreams of a beautiful world is what I call Romanticism. It may seek its heavenly city in the past or in the future; it may preach ‘back to nature’ or ‘forward to a world of love and beauty’; but its appeal is always to our emotions rather than to reason. Even with the best intentions of making heaven on earth it only succeeds in making it a hell – that hell which man alone prepares for his fellow-men.”

“It is often asserted that, in view of the situation in quantum theory, object and subject can no longer be sharply separated. 1 To use Heitler’s words, the ‘separation of the world into an “objective outside reality”, and “us”, the self-conscious onlookers, can no longer be maintained. Object and subject become inseparable from each other’. 2 This, according to Bohr, is due to ‘the impossibility of any sharp separation between the behaviour of atomic objects and the interaction with the measuring instruments which serve to define the conditions under which the phenomena appear’. 3 Heitler elaborates the point in some detail. ‘One may ask’, he writes, ‘if it is sufficient to carry out a measurement by a self-registering apparatus or whether the presence of an observer is required.’ And he arrives at the conclusion that the self-registering apparatus is insufficient, and that ‘the observer appears, as a necessary part of the whole structure, and in his full capacity as a conscious being’.”

“We are social creatures to the inmost centre of our being. The notion that one can begin anything at all from scratch, free from the past, or unindebted to others, could not conceivably be more wrong.”

“Always remember that it is impossible to speak in such a way that you cannot be misunderstood: there will always be some who misunderstand you.”

“Denying realism amounts to megalomania.”

“The more we learn about the world, and the deeper our learning, the more conscious, specific, and articulate will be our knowledge of what we do not know; our knowledge of our ignorance. For this indeed, is the main source of our ignorance - the fact that our knowledge can be only finite, while our ignorance must necessarily be infinite.”

“Science may be described as the art of systematic oversimplification.”

“No book can ever be finished. While working on it we learn just enough to find it immature the moment we turn away from it”

“While differing widely in the various little bits we know, in our infinite ignorance we are all equal.”

“No rational argument will have a rational effect on a man who does not want to adopt a rational attitude.”

“What we need and what we want is to moralize politics, not to politicize morals.”