"At least one distinguished ecologist, Ivar Mysterud, and a friend of the reindeer, thinks that even if there were an ecologically very innocent way of heavily reducing the population of a certain parasite that causes extreme pain to the reindeer, or of altering its habits, it should nevertheless not be carried out. The reason: it might disturb a relevant ecosystem. We know too little (the docta ignorantia of a field ecologist!). I agree that there is a presumption against it, but I disagree with his conclusion. The very prolonged, cruel sufferings of the reindeer count more. I am for radically reducing the population of the parasite even if it may be wrong according to L. If an ecosystem is dominated by pain-producing parasites, perhaps we might say its "beauty" diminishes? I am somewhat uncertain about how to interpret the term, and also about the possibility that human beings could preserve or enhance beauty by interfering."