When I taught the issue of egoism versus altruism in my Introduction to Philosophy class last semester, I wasn’t happy with my ability to explain why the choice is either-or. I’m able to effectively explain the evils of a fully altruistic life, in part thanks to Susan Wolf’s article on “Moral Saints.” (She draws different conclusions in that article than I do, but it works quite well for my purposes.) However, the next natural position for my students to adopt is that some mixture of egoism and altruism is the right answer: sometimes we should think of ourselves first and sometimes we should think of others first.

Obviously, that view is partially motivated by the false assumption that egoism demands callous indifference to others. However, it’s also due to a much deeper problem, namely the fact that the students don’t understand the fundamental opposition of egoism to altruism. They fail to appreciate that because they don’t think of their own lives in terms of any fundamental principles or ultimate values. They don’t think that a life needs to be so integrated.

So, dear readers, do have any suggestions on how I might show that egoism and altruism cannot be coherently mixed? How can I make reasonably clear that to attempt to sometimes adopt one policy and sometimes adopt the other cannot be done on any rational, principled basis, but would have to be a mere emotional decision?

Of course, my students won’t be obliged to agree with me. They’re welcome to defend any views they please in class and in their papers, so long as those views are supported by plausible arguments. However, I’d like to offer them compelling grounds on which to question a view that seems so natural to them.