In their entry for “legal positivism” in the Stanford Encyclopedia of Philosophy (SEP), Leslie Green and Thomas Adams define this theory of law as “the thesis that the existence and content of law depends [sic] on social facts and not on its merits.” But what is a “social fact,” and which social facts are relevant to law? One of the earliest-recorded responses to these difficult theoretical questions–and perhaps the most influential one–was offered by the person of Thrasymachus in Book I of Plato’s Republic, where in response to Socrates, he famously asserts that “justice is in the interest of the stronger.” Although Green & Adams do not mention Thrasymachus or The Republic in their SEP review essay, I would argue that all major strands of modern legal positivism can ultimately be traced back to Thrasymachus’s cynical but realistic conception of justice in Plato’s Republic. With this background in mind, I will now introduce simplified versions of the major theories or types of legal positivism.
First is Theory T1 (or legal positivism 1.0), “the command theory of law” put forth by English legal theorist John Austin (1790–1859). On this view, law is the command of a sovereign backed by force or some other negative sanction. Next is Theory T2 (or legal positivism 2.0), Austrian jurist Hans Kelsen’s (1881–1973) so-called “pure theory of law.” According to Kelsen’s abstract theory, individual legal norms are part of larger systems of law and all such norms or rules in a given system must ultimately be traced to a fictional “basic norm” of that system. Last is Theory T3 (or legal positivism 3.0), H.L.A. Hart’s (1907–1992) “rule of recognition” and “internal point of view” of public officials like judges and legislators. Stated in its most simplified form, law is neither based on force nor on a fictional basic norm; law is whatever guides or shapes the behavior of public officials. Law is whatever public officials think the law is.
We will explore the strengths and weaknesses of all three theories of legal positivism in future blog posts. For now, I just want to identify the influence of Thrasymachus on all three of these theories of law. To begin with, Austin’s command theory and the cynical notion that “justice is nothing but the advantage of the stronger” appear to be almost interchangeable. By definition, the sovereign in Austin’s command theory is “the stronger” in Thrasymachus’s famous formulation of justice. Next, with respect to Kelsen, the fictional “basic norm” in Kelsen’s pure theory of law appears to carry out the role of the sovereign or “the stronger” set forth in previous formulations of legal positivism. Moreover, to the extent actual systems of law benefit the powerful, one could argue that Kelsen’s “basic norm” is just a subterfuge to legitimate “the interest of the stronger.”
Last but not least, what about H.L.A. Hart? Are there any shades of Thrasymachus in Hart’s sociological-psychological theory of law? To the extent Hart’s realist theory of law emphasizes the behavior of public officials, don’t these officials, by definition, form a kind of “class” or elite who, collectively, play the role of “the stronger,” since they get to decide what the law is? We will return to Austin, et al., and further explore the connection between Thrasymachus’s formulation of justice and modern theories of legal positivism in our next few posts …