• We can deduce, often, from one part of physics like the law of gravitation, a principle which turns out to be much more valid than the derivation.

    Richard P. Feynman: We can deduce, often, from one part of physics like the law of gravitation, a principle which turns out to be much more valid than the derivation.
    "The Character of Physical Law". Book by Richard P. Feynman, 1965.