It is the merest truism, evident at once to unsophisticated observation, that mathematics is a human invention.

It is the merest truism, evident at once to unsophisticated observation, that mathematics is a human invention.

I can see no justification whatever for the attitude which refuses on purely a priori grounds to accept action at a distance ... Such an attitude bespeaks an unimaginativeness, a mental obtuseness and obstinacy.

The true meaning of a term is to be found by observing what a man does with it, not by what he says about it.

There is no adequate defense, except stupidity, against the impact of a new idea.

If a specific question has meaning, it must be possible to find operations by which an answer may be given to it ... I believe that many of the questions asked about social and philosophical subjects will be found to be meaningless when examined from the point of view of operations.

The operational approach demands that we make our reports and do our thinking in the freshest terms of which we are capable, in which we strip off the sophistications of millenia of culture and report as directly as we can on what happens.