And someone that brilliant must be a devil?" queried Galt, dryly. "Not at all," explained Donal, patiently. "But having such intellectual capabilitie… - Gordon R. Dickson

" "

And someone that brilliant must be a devil?" queried Galt, dryly.
"Not at all," explained Donal, patiently. "But having such intellectual capabilities, a man must show proportionately greater inclinations toward either good or evil than lesser people. If he tends toward evil, he may mask it in himself—he may even mask its effect on the people with which he surrounds himself. But he has no way of producing the reflections of good which would ordinarily be reflected from his lieutenants and initiates—and which, if he was truly good—he would have no reason to try and hide. And by that lack, you can read him.