I'm not asking about philosophers who wrote *about* dark or amoral ideas (like Nietzsche or Machiavelli), but someone for whom some emotional states, or better, intuitive insights, were simply absent or very diminished as a matter of their psyche.
What puzzles me is the motive: folk philosophy is largely driven by wonder, anxiety about death, a longing for “meaning”, moral dilemmas, or some pop debates such as free will. If a psychopath lacks some mental functions where they never get the need for folk philosophy, what would even draw them to write or read philosophy in the first place? Would the philosophy they produced look noticeably different?
Maybe they were forced into it as part of education coming from a noble family in per-modern era, but who were they?