A third variety of ad hominem argument is more subtle. Consider the following exchange:
Norm: The cold war is over, and bad relations between Cuba and the United States hurt both countries, so it is time for the United States to develop normal relations with Cuba.
Cliff: Yeah, so you can make a bundle importing cigars from those commies.
Cliff’s reply is an attack on the motives of Norm and not on the truth of what Norm said. Nor is Cliff denying that Norm has a right to speak. Yet the remark is not without some relevance—it is not off the wall. In a conversa- tional exchange, we rely on the integrity of the person who is speaking, and when we have reasons to believe that the person’s integrity is questionable, we sometimes say so. This is the significance of Cliff’s remark. Cliff points to a fact that gives some reason for us not to trust Norm’s integrity in a dis- cussion of the United States’ relations with Cuba.
Cliff’s attack might or might not be justified. If the only reason why Norm favors normal relations between the United States and Cuba is that this would enable Norm to make more money, then Cliff’s ad hominem attack is well founded. But if Norm’s real reason for saying what he does is that he honestly believes that normal relations would be beneficial both to the United States and to Cuba, then Norm’s position does not depend on any lack of integrity. In that case, Cliff’s attack is not well founded, even if it so happens that Norm would profit from normal relations.