Oh good, another off-topic discussion. The Wagner problem is not restricted to music and painting. Pontryagin and Teichmuller were anti-semetic, and Teichmuller showed up at Emmy Noether's lectures in his (Brown Shirt) uniform. Of course, mathematics is held to a higher standard than the personal life of the mathematician who discovered it. In chemistry, Ernst Haber provides a more extreme example. He won the Nobel Prize for his process of fixing nitrogen ("Fix" is jargon for getting it in a usable compound, namely ammonia) Without Haber's invention Malthus would surely have been proven right. But Haber was also responsible for the production of Zyklon-B gas and its uses in both World Wars, and it is reasonable to presume that his wifew's suicide was on this account