I don’t think making the Stone requires an evil act, or Dumbledore wouldn’t be an ally of Flamel, and he wouldn’t harbour the Stone in Hogwarts.
Or he may not know how it’s made. He says that Flamel assures him that Voldemort couldn’t possibly make the stone on his own, so clearly Dumbledore doesn’t consider himself fit to judge that.
if anything, this makes it more likely that the creation of the stone requires something Voldemort lacks—such as innocence, youth, or, oh heck, virginity.
Or he may not know how it’s made. He says that Flamel assures him that Voldemort couldn’t possibly make the stone on his own, so clearly Dumbledore doesn’t consider himself fit to judge that.
if anything, this makes it more likely that the creation of the stone requires something Voldemort lacks—such as innocence, youth, or, oh heck, virginity.
Tentative: Maybe it takes liking living things—Voldemort doesn’t seem to have any sort of generalized liking for anything but himself and his snake.