In his excellent recent essay “Revolutionizing Ethics,” David V. Johnson calls on leftists to reclaim the moral high ground from those he labels “moral sentimentalists.” He goes on to catalogue an impressive litany of such sentimentalists, from usual liberal suspects like New York Times columnists and Barack Obama to no less a personage than Prince Charles.

There can be no debating Johnson’s analysis that individual moral action has largely supplanted political solutions to today’s social ills. One need look no further than The Foundation for a Better Life’s “Values” ad campaign — which has plastered such platitudes as “Hard work. Pass it On.” and “Ambition is an earnest desire for achievement,” on billboards across the country — to find confirmation for Johnson’s claim that “[c]alling for everyone to be more ethical becomes a serious political platform, even a policy recommendation.” Moralists ascribe blame for structural problems on personal failings in order to obscure their defense of the way in which our society is organized.

But while I concur with Johnson’s analysis, I disagree heartily with his conclusion: that those of us on the Left must take back morality from the sentimentalists; that we must “revolutionize ethics.” Rather, I see an entirely different path forward for the Left: it’s high time to leave behind this idealistic kingdom of morality and rediscover the realm of self-interest. This is the only hope for our movement — to continue to base our politics on moral grounds is to condemn ourselves to continuing political irrelevance.

Take, for instance, the question of how we should combat climate change, which Johnson recognizes as “the most pressing crisis we face.” Here, moral considerations only unnecessarily complicate the issue. The obvious foundation on which a mass movement for sustainability could be built is not principled concern with our responsibility to the Earth, but shameful, slimy self-interest — the simple fact that if we don’t act now, life on this planet is going to get shitty in a few short decades.

Or take the example of labor unions. We don’t need to promote union membership solely by appealing to lofty ideals like “solidarity with your fellow worker” or “bringing democracy to the workplace.” Rather, the single most powerful argument in favor of unionization is the extra 20–30 percent that unionized workers earn in comparison to non-unionized counterparts.

This is not to say that we should leave moral principles like solidarity and democracy behind, only that such considerations must be partnered with serious attempts to show people how leftist policies would concretely improve their lives. The Left today excels at railing against the injustices of capitalism and imperialism; we fail, however to successfully express how systemic change is also just plain good for everyone. A renewed emphasis on our moral rectitude would move us that much further from a new mass movement on the Left.

Of course, a left understanding of self-interest must leave behind those pernicious adjectives “rational” and “individual,” which bourgeois economists have attached to the concept of self-interest for centuries. Our task today is to carefully separate these three concepts from each other, then discard the nonsensical positions that human behavior is always rational and that we can think about ourselves as abstracted from the communities which create us. Conceptualizing self-interest in newly non-rational and collective terms will be difficult, but well worth the effort should it result in a left newly revitalized by a fresh understanding of how mass movements appear, persist, and ultimately expire.