These would-be English Kings of Heavy Metal are eternally foiled by their stupidity and intractability. In the early Seventies their murky drone was all the more appealing for its cynicism — the philosophy that everything is shit, and a flirtation with pre-Exorcist demonic possession. Time has passed them by: their recent stuff is a quaint bore.
– Ken Tucker on Black Sabbath, The Rolling Stone Record Guide, 1979