"Heydrich had an incredibly acute perception of the moral, human, professional and political weaknesses of others. His unusual intellect was matched by the ever-watchful instincts of a predatory animal. He was inordinately ambitious. It seemed as if, in a pack of ferocious wolves, he must always prove himself the strongest and assume the leadership."
— Walter Schellenberg
"He was very young, very handsome, save that his eyes were too close-set; an outstanding example of that blond mixture of effeminacy and toughness which may be observed in any Teutonic night-club. He had immense drive, which was liable to carry him too far; total ruthlessness in the attainment of his own ends, which were wrapped up in personal ambition; no active enjoyment of cruelty except sometimes, perhaps, almost as an afterthought; and a devilish sense of humor. Vain as a peacock, but mockingly aware of his vanity, clever, perhaps too clever by half, and contemptuous of the clumsiness of most of his colleagues and superiors, he nevertheless could be clumsy in his use of force and, unlike Himmler, was liable to over-reach himself. He was dynamite, like a character in an American gangster story; and in the SS he was able to canalise his nihilism into a constructive purpose."
— Edward Crankshaw, Gestapo: Instrument of Tyranny (1956)
"The Nazis who talked about Heydrich after the war, were Nazis who survived, and thus had a vested interest in trying to downplay their own complicity and elevate Heydrich's. So we do need to keep that in mind. But still, the fact that, not just after the war, but during and before the war, other Nazis consistently recognized Heydrich as a terrifying and vile monster, says a lot about the man. [...] When you set him up like that, one expects Heydrich to be almost a force of supernatural evil, like a fucking Wolfenstein Nazi, like he's summoning demons and shit. The reality is that every single person listening to this knows at least one person with a personality similar to Reinhard Heydrich's. The most terrifying thing about this guy is that he was not a super anti-Semitic dude from the start. He was not a super committed Nazi from the start. His evil grew from the most mundane seed possible: He wanted to be a big man. [...] [Hitler] has demonic dreams from a very early age; these dreams of conquest and violence against his enemies. He follows a decades long plan to achieve them. That's not Reinhard Heydrich. Heydrich is a guy who wants to be important and respected, and that leads him to plan the Holocaust."
— Robert Evans, Behind the Bastards
