Jeffrey Kaplan takes a notoriously dense philosophical text and strips it down to its behavioral bones, revealing how a 19th-century theory of law tries to explain complex legal systems using nothing but gunshots and habits. This is not a dry summary of jurisprudence; it is a dissection of why reducing law to mere commands fails to capture the human experience of duty. For the busy professional trying to grasp the foundations of legal authority, Kaplan's breakdown of H.L.A. Hart's The Concept of Law offers a rare clarity on why the law feels different from a mugger's threat.
The Behaviorist Trap
Kaplan begins by setting the stage for Hart's critique of John Austin, a legal theorist whose work Hart aims to dismantle. The core of Kaplan's analysis rests on the concept of naturalism and its extreme offshoot, behaviorism. He explains that behaviorists reject private mental states as unscientific, insisting that only outwardly observable actions matter. "The theory of law that we're going to get from Austin is fundamentally a behaviorist theory of law," Kaplan writes. This framing is crucial because it exposes the limitation of Austin's approach: it attempts to build a legal system out of physical actions alone, ignoring the internal mindset of the people obeying the law.
This reductionist view leads to a stark conclusion about the nature of legal commands. Kaplan notes that under this framework, orders are merely "sounds coming out of the mouths of individuals," and sanctions are just physical acts like being "struck or imprisoned." The argument is compelling in its simplicity but ultimately fragile. By refusing to acknowledge the psychological reality of obligation, the theory struggles to explain why citizens follow laws when no one is watching.
"We're going to get from Austin as summarized by Hart an explanation for the existence of legal systems that only ever mentions outwardly observable things like behavior."
From Gunman to Government
To illustrate the gap between a criminal threat and a legal system, Kaplan walks the reader through Hart's famous "gunman scenario." He describes a robber demanding money with a threat of violence, then methodically modifies this scenario to see if it can evolve into a functioning legal system without invoking any internal mental states. The first modification Kaplan highlights is the shift from specific, one-time commands to general rules. "The standard form, even of a criminal statute, is general in two ways," Kaplan writes, noting that laws apply to a "general type of conduct" and a "general class of persons."
This distinction is vital. A gunman says, "Put the money in the bag now," but a law says, "Pay taxes every April 15th." Kaplan points out that this change doesn't violate behaviorist principles; it just changes the frequency and scope of the sounds made by the authority figure. However, the theory hits a snag when addressing the persistence of these commands. Kaplan explains that standard threats are fleeting, whereas laws must endure. "Disobedience is likely to be followed by the execution of the threat not only on the first promulgation of the order but continuously until the order is withdrawn," he notes. This requirement for perpetual enforcement is the second major step in transforming a robber into a sovereign.
Critics might note that even with these modifications, the behaviorist model still fails to explain why people obey laws out of a sense of duty rather than fear. Kaplan hints at this gap, acknowledging that Hart will eventually need to appeal to psychological states to fully explain legal systems, a move that behaviorists would reject.
The Efficacy of Habit
As the scenario evolves, Kaplan introduces the third modification: efficacy. For a system to be considered legal, it cannot just issue commands; those commands must actually work. "We must suppose that whatever the motive, most of the orders are more often obeyed by most of those affected," Kaplan writes. This introduces the concept of habit, which Austin and Bentham rely on to explain social order. The argument suggests that if people habitually obey, the system is valid, regardless of their internal reasons for doing so.
Kaplan then moves to the more complex fourth and fifth modifications, which concern the nature of the authority itself. He describes "internal supremacy," where the person giving the orders is not subject to the orders of anyone else. This transforms the gunman into a sovereign. "Within the territory of each country, there may be many different persons or bodies of persons giving general orders backed by threats and receiving habitual obedience," Kaplan explains. The goal is to show that even with all these behavioral tweaks—generality, persistence, efficacy, and supremacy—the resulting system still lacks the crucial element of legal validity as we understand it.
"The gunman scenario is described purely behavioristically... and then we're going to check each step."
The Missing Piece
The brilliance of Kaplan's commentary lies in how he prepares the reader for Hart's eventual rebuttal. By meticulously building a legal system out of nothing but observable behavior, he sets a trap. The resulting model looks like a legal system, but it feels hollow. It lacks the normative force that makes law distinct from organized crime. Kaplan's analysis suggests that the missing ingredient is the internal point of view—the belief that the rules ought to be followed, not just that they will be enforced.
This approach effectively demystifies a complex philosophical debate. By treating the text as a logical puzzle where Hart is trying to prove a negative, Kaplan makes the abstract concrete. He shows that while Austin's theory is elegant in its simplicity, it collapses under the weight of real-world legal experience. The behaviorist lens is too narrow to capture the full scope of human obligation.
Bottom Line
Jeffrey Kaplan's commentary succeeds by turning a dry theoretical critique into a narrative about the limits of scientific reductionism. The strongest part of his argument is the clear demonstration of how Austin's behaviorist model fails to account for the internal sense of duty that defines legal systems. Its biggest vulnerability is the assumption that readers are already familiar with the stakes of the naturalism debate, though Kaplan does a commendable job of bridging that gap. Watch for how Hart's eventual introduction of the "internal point of view" completely reshapes the definition of law in the subsequent chapters.