"Some fool has put the head of this nail on the wrong end." "You idiot, it's for the opposite wall!" To be sure, if the space of physical objects allowed motions of translation only, and not also rotations. That space has such geometry is a fantasy; experience shows otherwise. It is only experience that makes this complaint and the rejoinder a dialogue of madmen."

“To get at the meaning of a statement the logical positivist asks, "What would the world be like if it were true?" The operationist asks, "What would we have to do to come to believe it?" For the pragmatist the question is, "What would we do if did believe it?”

“In addition to the social pressures from the scientific community there is also at work a very human trait of individual scientist. I call it the law of the instrument, and it may be formulated as follows: Give a small boy a hammer, and he will find that everything he encounters needs pounding. It comes as no particular surprise to discover that a scientist formulates problems in a way which requires for their solution just those techniques in which he himself is especially skilled.”

“The price of training is always a certain "trained incapacity": the more we know how to do something, the harder it is to learn to do it differently.”

“We are caught up in a paradox, one which might be called the paradox of conceptualization. The proper concepts are needed to formulate a good theory, but we need a good theory to arrive at the proper concepts.”

“Every discipline develops standards of professional competence to which its workers are subject... Every scientific community is a society in the small, so to speak, with its own agencies of social control.”

“Experience is of particulars only.”