Philosophy shows itself to be alive when it raises, again and again, the deep concerns that plague man's reason; it dies when it presumes to have res… - Henry Margenau

... during the last two decades, there has been introduced into physical methodology a principle of utmost philosophical importance, easily rivaling that of relativity, and, in some respects, indeed that of causality. Discovered by Pauli in 1925, it immediately elucidate a whole realm of physical facts and was accepted by physicists with wide acclaim. Called the exclusion principle—or Pauli principle, or principle of anti-symmetry—it was embodied in the axiomatics of quantum mechanics; its pecular methodological significance passed out of view.

The combination of interest in physics and in philosophy was uncommon in the United States, and physicists who deviated from the narrow path were looked down upon by their colleagues. Philosophy of physics was definitely regarded as an aberrant, evasive sort of discipline, practiced by physicists who 'could not make it' in their straight profession and, in somewhat greater numbers, by philosophers whose knowledge of physics was inadequate.