“We find no sense in talking about something unless we specify how we measure it; a definition by the method of measuring a quantity is the one sure way of avoiding talking nonsense...”

“[Newton's calculations] entered the marrow of what we know without knowing how we know it.”

“Sir Hermann Bondi once wrote that so-called scientific progress does not consist so much in an advancement in science but rather in taking something that beforehand was not science and making it become a part of science itself.”

“The aim of this article has been to show that our most successful theories in physics are those that explicitly leave room for the unknown, while confining this room sufficiently to make the theory empirically disprovable. It does not matter whether this room is created by allowing for arbitrary forces as Newtonian dynamics does, or by allowing for arbitrary equations of state for matter, as General Relativity does, or for arbitrary motions of charges and dipoles, as Maxwell's electrodynamics does. To exclude the unknown wholly as a 'unified field theory' or a 'world equation' purports to do is pointless and of no scientific significance.”

“What I remember most clearly was that when I put down a suggestion that seemed to me cogent and reasonable, Einstein did not in the least contest this, but he only said, 'Oh, how ugly." As soon as an equation seemed to him to be ugly, he really rather lost interest in it and could not understand why somebody else was willing to spend much time on it. He was quite convinced that beauty was a guiding principle in the search for important results in theoretical physics.”

“[Science doesn't deal with facts; indeed] fact is an emotion-loaded word for which there is little place in scientific debate.”

... an “opportunity to allow the bees in one's bonnet to buzz even more noisily than usual.”

“Religion divides us, while it is our human characteristics that bind us to each other.”

“The fact that stares one in the face is that people of the greatest sincerity and of all levels of intelligence differ and have always differed in their religious beliefs. Since at most one faith can be true, it follows that human beings are extremely liable to believe firmly and honestly in something untrue in the field of revealed religion. One would have expected this obvious fact to lead to some humility, to some thought that however deep one's faith, one may conceivably be mistaken. Nothing is further from the believer, any believer, than this elementary humility. All in his power ... must have his faith rammed down their throats. In many cases children are indeed indoctrinated with the disgraceful thought that they belong to the one group with superior knowledge who alone have a private wire to the office of the Almighty, all others being less forturnate than they themselves.”