Leigh Johnson’s piece on friendly fire makes the case that we need friends who are willing to levy thoroughgoing attacks on our cherished philosophical convictions, and that this “friendly fire” is a sign of a solid friendship. Using Aristotle’s trichotomy of friendships of use, pleasure, and virtue, Johnson argues just as the truest form of friendship is one of two souls united in the project of virtue, the highest form of friendship is one that admits of vigorous debate: I was having a conversation with one of my oldest and closest friends (Dr. Trott) a few weeks ago, and we were both genuinely perplexed by people who take disagreement to indicate some fundamental devaluation of the other person or, alternatively, people who take disagreement…