Abraham Kaplan quotes:

Mathematics is not yet capable of coping with the naïveté of the mathematician himself.

Experience is of particulars only.

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.

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?

Give a small boy a hammer and he will find that everything he encounters needs pounding.

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.

A philosophy which speaks, even indirectly, only to philosophers is no philosophy at all; and I think the same is true if it speaks only to scientists, or only to jurists, or priests, or any other special class.

There is nothing more inspiring than having a mind unfold before you. Let people teach who have a calling. It is never just a job.

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 forever asking Nature whether it has stopped beating its wife.

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.

A problem is something you can do something about. If you can't do something about it, then it's not a problem, it's a predicament. That means it's something that must be coped with, endured.