John Bossy

“In trying to find out what Bruno thought of his priesthood, we now have a serious problem which we did not have before. In Venice, he told his fellow-prisoners that he was an enemy of the mass, and thought transubstantiation a ridiculous idea and the Catholic ritual bestial and blasphemous. He compared the elevation of the host to hanging somebody on a gallows, or perhaps to lifting him up on a pitchfork. He told somebody who had dreamt of going to mass that that was a terrible omen; and he performed a mock mass with Ovid's Art of Love instead of a missal. He joked about hungry priests going off from mass to a good breakfast. He spoke particularly ill of the mass as a sacrifice, and said that Abel, the archetype of the sacrificing priest, was a criminal butcher who was rightly killed by the vegetarian Cain. A phrase he used elsewhere, apparently about Christ's passion and not directly about the mass itself, seems nevertheless to express rather exactly his attitude to is: he called it 'some kind of a cabbalistic tragedy'.”
― John Bossy, Giordano Bruno and the Embassy Affair