Spock's supporters countered that these criticisms betrayed an ignorance of what Spock had actually written, and/or a political bias against Spock's left-wing political activities. Spock himself, in his autobiography, pointed out that he had never advocated permissiveness; also, that the attacks and claims that he had ruined American youth only arose after his public opposition to the Vietnam war. He regarded these claims as ad hominem attacks, whose political motivation and nature were clear.[22][23]