Gizbert-Studnicki considers how we are to understand the social thesis and whether the social thesis, properly understood, can handle Hume’s guillotine, that is, the problem also known as the fact-value gap or the is-ought problem that Hume first articulated in book III, part I, section I of his A Treatise of Human Nature (1739), according to which one may not logically derive an ‘ought’ from an ‘is’. Having distinguished three interpretations of the social thesis – the social sources thesis, the sources thesis and the social fact thesis – he focuses on the social fact thesis, which is a metaphysical thesis according to which legal facts are ultimately determined by social facts alone. Gizbert-Studnicki then considers three different ways of understanding the relation between social facts and legal facts along the lines of the social fact thesis, namely, reduction, supervenience and grounding. He maintains that while all three relations are more or less problematic, the grounding relation is to be preferred, and that adopting the idea of grounding helps us avoid Hume’s guillotine, since grounding is not a matter of entailment but a metaphysical relation that holds between facts.

On August 19, 1815, a dozen years before undertaking Winterreise, Franz Schubert composed a song that treads similar poetic ground. Like the winter wanderer of Wilhelm Müller’s cycle, the protagonist of Johann Wolfgang von Goethe’s “An den Mond” (D259; To the Moon) roams through a natural landscape evoking inner terrain; the moonlit wood and valley conjure the recesses of his (or her) mind, intimating a journey of self-discovery. The protagonist’s present solitude, recollection of joyful and troubled times, glancing reference to faithless love, direct address to a river, allusion to the harshness of winter, mention of his own song, and mysterious closing reference to wandering by night through the labyrinth of the heart all anticipate ways that Müller, in a darker mode, conveys existential isolation and suffering in Winterreise.

As Redondo explains, Eugenio Bulygin’s legal positivism embraces the separation thesis, a version of the social thesis (which he calls the ‘social sources thesis’), and an indeterminacy thesis, according to which law is sometimes indeterminate, giving judges discretion to decide cases. Bulygin holds that law can be necessarily normative only in a weak, relative sense. Redondo explains that Bulygin espouses two methodological theses that are positivist – that the task of legal philosophers is to explicate legal concepts and that we need to maintain in our legal thinking a distinction between norms and normative propositions – and that he espouses three substantive theses that are also positivist – that legal positivists must adopt a concept of relative normative validity to account for the existence of legal rights and duties, that legal interpretation must proceed on the assumption of linguistic conventionalism and that there is a fundamental and unbridgeable distinction between prescriptive and power-conferring norms. These theses can be said to be positivist because they all, one way or another, enable a value-neutral study of law, i.e. so-called methodological legal positivism.

Green considers a strong version of the semantic thesis, according to which legal statements are descriptive statements solely about social facts. He starts from the foundational thesis of positivism, the social thesis, which has it that the existence and content of the law are ultimately based solely in social facts about a community. But he notes that there are two versions of this thesis. Under the reduction version, a legal system and its laws consist of social facts. Under the assignment version, they are not social entities at all; they are norms, understood as abstract objects. But the grounds for assigning these abstract objects to a community are ultimately solely social facts. Focusing on the assignment version, he asks whether the semantic thesis follows from the social thesis, and, if that answer is no, the extent to which legal statements actually conform to the semantic thesis. He argues that assignment positivists can conclude that the answer is negative because, for them, legal statements describe abstract objects. For Green, this simple account of the semantics of legal statements is superior to expressivist accounts and to Raz’s account.

Rodriguez-Blanco clarifies John Finnis’s objection to legal positivism in the shape of Hart’s theory, namely, that it is unstable because it uses the notion of an internal point of view, which does not have sufficient discriminatory power to distinguish between good and less good legal norms, between rational and non-rational court decisions, etc. Finnis’s view is that understanding a human action in law involves understanding what the point of the action is, that such understanding requires use of the Aristotelian focal meaning (or central case) methodology, that Hart’s internal point of view does not involve focal meaning and therefore cannot be used to understand the point of human actions, and that Hart’s theory is thus unstable. Rodriguez-Blanco argues that Anglophone legal philosophers’ focus in the past fifty years on Dworkin’s critique of Hart’s legal positivism has meant that they missed an opportunity to learn, through Finnis’s critique of Hart’s theory, about the philosophy of practical reason and the theory of action, and to contribute significantly to debates about normative questions, the nature of law and its relation to agency, reasons for action, and goodness.

The protagonist of Winterreise wanders through a landscape that is both real and imagined. Banished from one home but unable to conceive another, he follows a path that circles back on itself repeatedly, leading only to exhaustion and defeat. Yet while the singer of Winterreise appears to inhabit a lonely landscape, Wilhelm Müller’s verses and their musical setting by Franz Schubert would also have evoked a concrete social world for their audiences, that of the road (Landstrasse). The road, by its very nature, was filled with people on the move, some of them (journeymen, pilgrims) heading purposefully from one place to another, but others with no particular destination, whose poverty, criminality, or “dishonorable” status banished them from their towns and villages. These last types, the “wandering people” (fahrendes Volk), had become well established as an object of public fascination and state scrutiny by the eighteenth century.

Müller’s poetic cycle Die Winterreise and Schubert’s song cycle Winterreise bring together two themes – the winter season and the experience of travel – that both appear in earlier literature and song. This chapter explores European and especially German precursors to Winterreise, focusing on the eighteenth and early nineteenth centuries.

Troper considers five types of legal positivists in French legal thinking, namely, the exegetical school, the sociological school and Léon Duguit, Carré de Malberg, the Vichy scholars, and the analytical legal positivists. He explains that Carré de Malberg put forward a theory of positive law that aims to be descriptive, according to which positive law is a product of the will of the state and the state possesses an innate capacity to obligate the citizens by means of its laws. He points out, however, that while Carré de Malberg’s description of French positive law aims to reveal an essence of the state, in reality the description proceeds from a set of abstractions that reflect his own normative theory of the state; and that this means that Carré de Malberg, while professing to espouse a methodological version of legal positivism, is actually closer to defending ideological positivism.

Kramer explains how H. L. A. Hart reinvigorated legal positivism by disconnecting it from the command theory of law defended by his predecessors Bentham and Austin; by introducing through his own theory of law some new and fruitful concepts into legal thinking, such as the internal point of view, the distinction between primary and secondary rules, and the idea of a rule of recognition; by clarifying the meaning of and reasons behind the separability of law and morality through considering the many different ways in which law and morality are, or could be, connected; and by introducing the idea of the minimum content of natural law and clarifying the relation between this and the separability of law and morality. Kramer explains: even though a legal system can fulfil its basic function of securing the conditions of civilisation only if it includes rules prohibiting murder, assault, fraud, etc., the relevant protection provided by the legal system against such misconduct need not be extended to all groups of citizens. Consequently, because no true moral principles would permit this, Hart’s account does not reveal any necessary connections between those principles and legal norms.

Tamanaha discusses the thesis of social efficacy. Having explained the import of the thesis, he argues that it is problematic in a number of ways. To begin with, not only are many legal systems not socially efficacious, because in many situations significant parts of the population do not obey the law, but it is also the case that two (or more) legal systems may be efficacious in the same society. Moreover, he argues, law-obedience, which is required by the social thesis and which involves as a conceptual matter at least a conscious attempt on the part of the citizens to follow the law, cannot be squared with the true empirical claim that many, perhaps most, people do not really know what the law requires of them; and this in turn means that we need a different conception of social efficacy, namely, one according to which the social efficacy of law is to be found in the constitutive use of law by government officials in combination with the activities of legal professionals who work to facilitate the aims of the people and organisations that hire them.

Baum Levenbook explores another criticism made against legal positivism. As she explains, Mark Greenberg objects to legal positivism, first, that it is a mistake to hold that legal facts are determined solely by social facts and, second, that the content of authoritative pronouncements, such as statutes, is determined by their linguistic content. But, she points out, Greenberg’s first objection is premised on the mistaken assumption that the nature of law requires the connection between legal facts and the determinants of legal facts to be, as Greenberg puts it, ‘rationally intelligible’, and the second objection is based on the equally unwarranted assumption that it is part of the nature of law to operate in such a way as to ensure that legal obligations are genuinely binding.

Kirste discusses legal scholars who were active in the nineteenth and twentieth centuries, identifying four main types of German legal positivism – jurisprudential, sociological, naturalistic, and statutory positivism – and a fifth type that he calls the general theory of law. His idea is that these theorists were legal positivists because they shared an epistemological aim, namely, establishing legal science as a science in its own right, independent of both the natural and the social sciences, and because they held that the only law is positive law in the sense of enacted norms or customary norms. He considers the theories of Hans Kelsen and Gustav Radbruch as examples of legal positivism. He points out that legal positivism lost its dominance in the wake of the post-World War II revival of natural law theory but soon reasserted its influence through the likes of Ota Weinberger, Niklas Luhmann, and Norbert Hoerster. He also notes that, since the late 1960s, authors such as Peter Koller and Ottfrid Höffe have focused on overcoming the gulf between natural law theory and legal positivism.

Bix considers that Joseph Raz might not be willing to accept that legal positivism is a theory, or stance, that is sufficiently well-defined to be captured in a few main tenets, thinking of it rather as a tradition of legal thinkers held together in a rather loose way. Bix focuses his discussion on Raz’s version of the social thesis, the so-called sources thesis, according to which all law is source-based, in the sense that the existence and content of the law is determined using exclusively factual (social) considerations. Bix considers Raz’s two main arguments in support of the sources thesis – the argument from authority and the argument from different functions – as well as certain objections to these arguments put forward by other legal philosophers.

A solitary wanderer journeys through a strange, desolate landscape, bracing himself against the harsh weather. He repeatedly interrupts his travels to observe and reflect upon the natural world around him: striking landscapes, flora and fauna, and mysterious, seemingly magical atmospheric phenomena. This wanderer, of course, is the unnamed speaker in Wilhelm Müller and Franz Schubert’s Winterreise – but his fictional travels mirror in interesting ways the real-life adventures of some early nineteenth-century scientific explorers and naturalists.