At the front of Handbook of Analysis and its Foundations are these four amusing but relevant


In dealing with mathematical problems, specialization plays, as I believe, a still more important part than generalization. Perhaps in most cases where we seek in vain the answer to a question, the cause of the failure lies in the fact that problems simpler and easier than the one in hand have been either not at all or incompletely solved. All depends, then, on finding out these easier problems, and on solving them by means of devices as perfect as possible and of concepts capable of generalization. -- David Hilbert

Logic sometimes makes monsters. During half a century we have seen the rise of a crowd of bizarre functions which seem to try to resemble as little as possible the honest functions which serve some purpose. No longer continuity, or perhaps continuity but no derivatives, etc. Nay, more: from the logical point of view, it is these strange functions which are the most general. Those which one meets without seeking, no longer appear except as a particular case. -- Henri Poincare

Mathematics belongs to man, not to God. We are not interested in properties of the positive integers that have no descriptive meaning for finite man. When a man proves a positive integer to exist, he should show how to find it. If God has mathematics of his own that needs to be done, let him do it himself. -- Errett Bishop

He considered, perhaps in his moments of less lucidity, that it is possible to achieve happiness on earth when it is not very hot, and this idea made him a little confused. He liked to wander through metaphysical obstacle courses. That was what he was doing when he used to sit in the bedroom every morning with the door ajar, his eyes closed and his muscles tensed. However, he himself did not realize that he had become so subtle in his thinking that for at least three years in his meditative moments he was no longer thinking about anything. -- Gabriel Garcia Marquez (novelist)