Richard Posner’s Legal Pragmatism

John J. Mearsheimer’s anthropology and Richard Posner’s legal pragmatism represent fundamentally different and often opposing views of human nature and political decision-making.
Mearsheimer’s anthropology argues that humans are “profoundly social beings” shaped by intense socialization, innate tribal sentiments, and strong attachments to their groups. He contends that we are born into societies that define our identities, making individualism secondary.
In contrast, Posner’s pragmatism—often linked to his “law and economics” background—views individuals largely as rational, utility-maximizing actors. Posner’s “everyday pragmatism” rejects “abstract” moral and political theory in favor of a “consequentialist” approach, where decision-makers look at the factual outcomes of a policy to see if it makes people “better off”.
A significant critique of Posner is his failure to account for law’s “expressive, value-shaping function”. Critics note that Posner treats people as having “fixed preferences” and views law merely as an instrument to create incentives for behavior modification. Mearsheimer’s anthropology would align with this critique, as he emphasizes that societies and their institutions actively shape the values and identities of individuals through socialization. To Mearsheimer, law is not just a tool for economic efficiency; it is part of the social fabric that constitutes who we are.
Posner famously dismisses “abstract” moral and political theory as “useless” or a “distraction,” arguing that judges should focus on practical consequences. Mearsheimer, however, argues that “reason” is the least important way we determine preferences, and that our moral codes are largely inherited from our family and society. From Mearsheimer’s perspective, Posner’s attempt to discard “abstract” theory is itself a socialized preference—a product of the specific “academic” tribe to which Posner belongs—rather than a neutral, objective way to view the world.
Posner’s pragmatism is often criticized for its lack of an “objective moral compass,” as he believes that when people disagree on fundamental moral questions, theory is unlikely to help. He relies on empirical evidence to guide decisions toward “beneficial” results. Mearsheimer’s anthropology would suggest that Posner’s definition of “beneficial” is inevitably tied to the specific social and cultural context he inhabits. Because Mearsheimer views humans as tribal and deeply attached to their specific groups, he would likely argue that a judge’s decision-making cannot be purely “consequentialist” in a vacuum; it is always filtered through the social values the judge has been socialized to hold.
If Mearsheimer’s anthropology is correct, Richard Posner’s pragmatic vision is built on a “delusion”—the liberal belief that we can function as atomistic, rational actors who discard our social and tribal baggage to make purely instrumental decisions based on “facts”. For Mearsheimer, Posner is essentially an “Enlightenment” thinker who underestimates the power of the “social nature of human beings” and the way tribal loyalties and socialization—not just “costs and benefits”—drive the human experience.