What he engaged in was a black mass-a Christian heresy.

T'ron, we at Benden have had only one queen dragon-at a time-for so many generations that there are those who denounce the legends of queens in battle as black heresy!

This actually is the blackest heresy, I admit.

A small number saw certain kinds of dream as actual memories of a world other than the one into which the dreamer and the listener had been born to live and die, but this was treated in most faiths as a black heresy.

All of which is the blackest heresy for a philospher, of course, because rational thought is in peril if the thinker cannot be seen as being in full command of his utterances.

"That's black heresy."