True. I have read the history of the Reformation by Merle D'Aubigny, and also the Reformation in the Time Of Calvin, and also Wylie's work, etc. I find that most people that refer to Calvin, have never even read that much, let alone what he wrote. A case in point, is Calvin with Michael Servetus. They think Calvin was the one that desired his execution by pyre as if some 'protestant pope', but Calvin actually tried to mitigate the pyre, and the execution was actually carried out by the council (syndics) of Geneva (issued Oct. 26th, ""Let him," so ran the decree of the Council, as described in the Register, "be condemned to be led to Champel, and there burned alive, and let him be executed tomorrow, and his books consumed." 5 (Rilliet, page 208), James A Wylie, History of Protestantism, Volume 2, Book 14, Chapter 22, page 334").
"At this supreme hour one man alone comes forward to attempt a mitigation of the punishment of Servetus. Who is that man? He is John Calvin. He earnestly interceded with the Council, not that the unfortunate victim might (335) be spared, but that the sword might be substituted for the fire; but he interceded in vain. "It is to him, notwithstanding," says Rilliet, "that men have always imputed the guilt of that funeral pile, which he wished had never been reared." ...
... As yet Servetus was ignorant, that he was to die by fire. Calvin had earnestly besought the Council that the miserable man might be spared this terrible surprise, but he had pleaded in vain. The magistrates would not permit him to influence their proceedings in the matter, even to the extent of substituting the sword for the stake." (ibid., 335)
As for the death to heretics, that was very much a part of the existing 'state' laws at the time.