Dostoevsky's characters are unbelievably, almost painfully fleshed out, leading the German romantic philosopher Friedrich Netzsche to proclaim: "Dostoevsky [is] the only psychologist, incidentally, from whom I had something to learn; he ranks among the most beautiful strokes of fortune in my life." In addition to the tormented killer Raskolnikov, Crime and Punishment introduces Porfiry, the brilliant investigator assigned to the murder case, and Sonia, a despoiled but pious woman devoted to Raskolnikov. Through his interactions with these two apparent opposites, Raskolnikov confronts his conscience, and learns that only through suffering can one find true happiness.