The peculiar sickness MacLeish describes isn't moral failure—it's a kind of spiritual parasitism, where the object of our hatred becomes our unwilling master. A person organized entirely around what they despise has surrendered their autonomy to that very thing; they wake thinking of it, plan around it, measure their days by opposition to it. Consider the political partisan who knows every flaw in the opposing side better than any virtue in their own—their identity has calcified into negation, and they'll never feel the lightness of someone building something simply because it matters to them, rather than because it wounds an enemy.