Jeffrey Kaplan dismantles a pervasive misconception in legal theory: the idea that if law is merely a social construct, it cannot be morally wrong. In a field often bogged down by dense abstraction, Kaplan's central claim is strikingly accessible yet philosophically rigorous: law is a social phenomenon, sustained entirely by human thought and action, much like money or fashion trends, but this does not mean it is immune to moral critique.
The Social Fabric of Law
Kaplan begins by grounding the abstract concept of "legal positivism" in tangible examples, arguing that the existence of law depends on collective human belief rather than divine mandate or inherent nature. He writes, "The value of money is a social phenomenon... its existence... depends on the continued actions and thoughts of people." By comparing legal systems to the unspoken "elevator rule" of facing the door, he illustrates how complex social structures persist only because we collectively agree to sustain them. This framing is effective because it strips away the mystique of the law, revealing it as a human invention rather than a cosmic truth.
The author posits that legal facts are ultimately social facts. "Legal facts that is facts about what the law is are ultimately social facts," Kaplan explains, noting that a law against jaywalking exists only because people wrote it, voted on it, and continue to believe in its authority. This distinction is crucial for understanding the modern legal landscape. Critics might argue that reducing law to mere social agreement ignores the profound sense of moral obligation many feel toward the rule of law, but Kaplan's point is descriptive, not prescriptive; he is explaining what law is, not why we should obey it.
Law is something that was posited into existence by human thought.
The Positivist vs. The Natural Law Theorist
The commentary then pivots to the great debate in jurisprudence: the clash between legal positivism and natural law theory. Kaplan clarifies that natural law theorists believe an unjust law is not truly law at all, citing Martin Luther King Jr.'s famous assertion from the Birmingham Jail: "I would agree with St Augustine that an unjust law is no law at all." Kaplan contrasts this with the positivist view, which maintains a "separation thesis." As he puts it, "There is no necessary connection between law and morals or law as it is and law as it ought to be."
This separation is often misunderstood as a moral failing of the positivist. Kaplan anticipates this, writing, "Does that mean that like legal positivists think that law should not be informed by morality? No no no no no no no no no no." He argues that the positivist framework actually offers a clearer way to critique bad laws. By admitting that a segregation law is law (because it was enacted through proper social procedures) but is also evil, the positivist avoids the semantic gymnastics required by natural law theorists who must deny the law's existence to condemn it.
The Power of Clear Distinctions
Kaplan's analysis of H.L.A. Hart and John Austin further solidifies the argument that legal systems are built on psychological states and patterns of behavior. He notes that Hart's theory is "ultimately a psychological theory of law" because it explains legal systems through "thoughts in terms of psychology." This is a powerful reframing for busy readers who might assume legal philosophy is about finding eternal truths. Instead, Kaplan suggests it is about understanding the mechanics of human cooperation and authority.
The author's refusal to let the distinction between "is" and "ought" collapse is the piece's intellectual anchor. He argues that natural law theorists "have to do this kind of weird thing to explain what Martin Luther King Jr... was up to," forcing them to claim that unjust laws cease to be laws. In contrast, the positivist can simply state: "There are these laws... they make interracial marriage illegal... that's what the law is and those laws are evil." This clarity allows for a more direct moral confrontation with the legal system.
You can figure out what the law is before or separate from figuring out what the law ought to be.
Bottom Line
Kaplan's strongest contribution is his ability to demystify legal positivism, showing it not as a defense of tyranny but as a tool for clearer moral criticism. The argument's greatest vulnerability lies in its reliance on the reader accepting that social facts can fully explain the binding nature of law, a point that natural law scholars will fiercely contest. For the reader, the takeaway is clear: understanding law as a human construct does not diminish its power; it simply places the responsibility for its morality squarely on our shoulders.