The first version of the fact/value distinction is often traced to Hume. In a famous passage of his Treatise of Human Nature (1739), Hume remarks that: “In every system of morality…the author proceeds for some time in the ordinary ways of reasoning…when all of a sudden I am surprised to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, “tis necessary that it should be observed and explained; and at the same time that a reason should be given; for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.” There is some controversy surroundings the proper interpretation of this passage.Footnote 8 On one influential reading, however, Hume is said to be arguing for a hard distinction between the is and the ought. Some even refer to this argument as “Hume’s Law” or “Hume’s guillotine”, because it sharply and fully severs the realms of fact and value.Footnote 9 When combined with “Hume’s fork”, the claim that we can only have true knowledge about the empirical world, it leads to the conclusion that the concept of “moral knowledge” must be a contradiction-in-terms.

The second version of the fact/value distinction may be traced to Kant’s first and second critiques, which were partly an attempt to refute Humean skepticism. Hume was skeptical about the possibility of causal knowledge of the natural world. In his Essay Concerning Human Understanding, recall, Hume argued that we cannot make logically valid inferences about causality based on empirical observations, because we can never observe all instances of a phenomenon. Just because the sun rises each morning does not logically entail that it will do so tomorrow! Kant was not convinced. He believed that the natural sciences had generated causal knowledge. The real problem was to understand how they had done so. The Critique of Pure Reason was his answer. In essence, Kant argues that causal relations are not relations between things as they are “in themselves” (the “noumena”) but rather between things as they are given to us in experience (the “phenomena”). Put more plainly, Kant argued that our minds are not just passive receptacles for sensory experience. They structure sensory input in a particular way. In terms of certain “categories” like time and space, for instance. Some of these categories, he argues, are prior to all experience. They are “a priori.” Perceptions of causality follow from these a priori categories, especially those of time and space. Thus, the “laws of nature” are ultimately grounded in the structures of human perception, rather than in the nature of “things in themselves.” How things really are “in themselves” we cannot know. There are limits to human reason.

Kant was also dismayed by Hume’s emotivist approach to ethics and his attendant claim that reason should be “the slave of the passions.” Kant hoped to show that our moral duties can be rationally derived and that reason should rule the passions. In the Critique of Practical Reason, Kant therefore begins from the (mostly tacit) premise that all human beings are autonomous rational agents. From this it follows that they are ends in themselves. Our moral duty is therefore to treat ourselves and others as ends, and never as means. Thus, we should never allow our rational wills to be the instrument of our sensual desires. Likewise, we should never use others as a means to our personal ends. The various versions of the “categorical imperative” are all attempts to articulate this basic duty. Perhaps the most famous version is presented in the Groundwork: “Act only according to that maxim whereby you can, at the same time, will that it should become a universal law.” It is important to note that Kant’s ethics are more procedural than substantive; they give us rules for moral reasoning rather than for moral action.

Note, too, that there is a deep tension between Kant’s epistemology and his ethics. His epistemology assumes that the natural world is governed by causal laws. His ethics demands that human action be governed by moral laws. But human beings are embodied creatures; they inhabit both worlds. How can their actions be governed by two different sets of laws? Put plainly, how is free will possible in a world of causal determinism? Kant “solves” this problem by appealing to the mysterious, noumenal faculty of “the will”, a faculty that somehow transcends but supervenes on nature.

The fact/value distinction enters into modern social science by two principal routes. The first is “logical-positivism”, an Anglo-Austrian intellectual movement that had a profound influence on the philosophy of science during the first half of the 20th century. Ludwig Wittgenstein was a member for a time, and Karl Popper was a hanger on. Logical positivism was influenced by Kantian idealism and British empiricism and sought to combine elements of both. From Kant, it took the view that our experience of the world is influenced by the categories of our understanding. For the logical positivists, however, the key “categories” were linguistic ones. And the main job of philosophy was to apply the rules of logic to police our use of language. What logical positivism took from British empiricism is a view of facts as unmediated sensory impressions, and of causal laws as a “constant conjunction” between such impressions. The “falsificationist” methodology of Karl Popper is one fruit of this synthesis.Footnote 10

Another, more relevant in this context, is Rudolf Carnap’s famous distinction between three types of judgments: 1) “synthetic”, meaning judgments with an empirical element, which can be falsified via observations. 2) “analytic”, having to do with the proper definition of concepts; they can be logically falsified. 3) “nonsensical”, the category in which moral judgments reside, because they cannot be empirically evaluated or logically analyzed.Footnote 11 On this reading, “facts” are based on unmediated sensory experience as rendered in logically coherent language, while “values” are subjective, emotional responses to the world.

The second route by which the fact/value distinction entered into contemporary social science is via the “methodological” essays of Max Weber.Footnote 12 As is well known, Weber’s views were deeply influenced by Kant, but also by Nietzsche and the German Historical School.Footnote 13 Let us begin with Weber’s theory of values. Weber rejected Kant’s claim that moral duties could be firmly grounded in reason. Indeed, in his view, the ends of our action are ultimately irrational – a matter of pure decision rather than rational deliberation. For example, there is, in his view, no rational reason why we should value truth over beauty or the erotic over the political. Our decision to devote ourselves to one “ultimate value” rather than another, he proposes, is fundamentally arbitrary. To this extent, Weber accepted Nietzsche’s nihilism. But only to this extent. While our choice of ends is finally irrational, Weber maintained, we can still try to be as clear as possible about what these ends are and as efficient as possible in pursuing them. To this degree, rationality might still play a role in ethics, namely, qua formal and instrumental rationality.

Weber often portrays our choice of ends as a choice between a finite set of “ultimate values.” But where do these “ultimate values” come from? How is the choice set defined? In his famous essay on “Religious Rejections of the World”, Weber attempts an answer. There, he distinguishes seven “value spheres” or “life orders” (religious, familial, political, economic, scientific, aesthetic and erotic) and discusses their inner logics and the profound “tensions” between them (between the Sermon the Mount and the demands of nationalism, for instance). He argues that these value spheres have become increasingly “rationalized” (internally) and increasingly “differentiated” (externally) over the last two millennia. The initial impetus for their crystallizion, he proposes, was the appearance of “world-rejecting religions” such as prophetic Judaism and Western Christianity, which posited a metaphysical rupture between a mundane and supramundane realm. This seminal rupture, he argues, was the catalyst for all that follows. Weber thereby suggests that this particular constellation of value spheres, seven in number, is a contingent product of Western history. The implication would seem to be that other world-rejecting religions, such as Hinduism and Buddhism, will have generated other sets of ultimate values. In this way, Weber conjoins the cultural relativism of the Historical School to Kantian proceduralism and Nietzschean nihilism – an uneasy amalgam at best.

Weber’s view of “facts” will be more familiar to most readers. It is related to his theory of values. In the social world, unlike the natural world, Weber maintains, values can themselves be causes insofar as they become ends of human action (which is not to say that values as Weber defines them are the sole or even predominant ends). Thus, the social sciences must use hermeneutic methods -- “interpretation” (Verstehen). Indeed, Weber argues that an “adequate” explanation of a social phenomenon must be premised on an adequate interpretation of the relevant actions. Moreover – and this is key – an adequate explanation will be fully transitive, both historically and culturally. In Weber’s (in)famous phrase, it will be just as compelling to “the Chinaman” as the Westerner.

How so? How does Weber reconcile this claim to factual objectivity with his commitment to cultural relativism? By means of his famous distinction between “value relations” (Wertbezüge) and “value neutrality” (Wertfreiheit). Cultural values will inevitably enter into our choice of research questions. However, they can – and must – be kept out of our research findings. The social and natural sciences cannot provide us with any guidance as to how we should live or what sort of society we should prefer, he says, and they should never pretend to do so. But they can help us choose the best means to our own personal or political ends. Achieving them, however, will necessarily involve struggle against those who hold opposing ends. And such struggles can only be resolved through politics, which, for Weber, means conflict.

At first glance, the positivist and interpretivist versions of the fact/value distinction may seem quite different, even opposed. And with regard to their theories of value, they are. Carnap banishes ethics to a realm of “nonsense” ruled by emotion. Weber keeps ethics within the bounds of reason, while diminishing the powers of reason. But there are striking similarities as well. This is perhaps most obvious with respect to their theories of facts. Both Carnap and Weber insist that there is an intransitive realm of fact that is clearly bounded from the influence of value. The similarities also extend to their understanding of values. Both understand values as subjective and relative. In this regard, they are far more radical than either Hume or Kant. Hume still believed that all human beings had shared moral sensibilities. Kant still believed that an autonomous human reason led to universal moral obligations. They were not nihilists. Carnap and Weber were.

Their shared nihilism arose out of a certain form of “moral imaginary.” By “moral imaginary”, I mean a set of interlinked background assumptions about the interrelationship of nature, self and society that are mostly unarticulated. Footnote 14 Both, to begin, embraced a fully mechanistic and “disenchanted” view of nature, that was shorn of any final purpose or inherent meaning. This was the heritage of Western science, or at least of a certain understanding of it.Footnote 15 Second, both presumed a highly disembedded and clearly bounded view of the self.Footnote 16 They imagined human persons as autonomous “wills” endowed with capacities of self-creation and value-projection. These selves were no longer part of nature in any meaningful sense, indeed, they were selves precisely insofar as they asserted themselves against nature. Thirdly, and finally, both inclined towards a highly atomistic and agonistic view of the social world. They tended to view human societies as aggregations of opposing and conflicting wills that were channeled and contained via markets and states. The crucial point to notice here is that the fact/value distinction presumes, not just a certain understanding of epistemology and ethics but, more than that, a certain ontology as well. It is suspended in a wider web of beliefs.Footnote 17 Does the web hold?