Hume Against the Grain: The Is/Ought Rupture as a Proto‑Deconstructive Gesture

AI art

“In every system of morality, which I have hitherto met with, I have always remarked, that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when 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, it is 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. But as authors do not commonly use this precaution, I shall presume to recommend it to the readers.” (David Hume, A Treatise of Human Nature, book 3, part 1, section 1)

Introduction

Few passages in moral philosophy have generated as much debate as David Hume’s famous remark that philosophers “of a sudden” slip from factual copulas—is, is not—to prescriptions—ought, ought not—without explanation (Hume, 1739/2000, p. 302). The sentence is usually treated as the seed of the modern “is/ought problem,” yet its rhetorical profile resembles the methodological double step Jacques Derrida later calls double reading. This essay reconstructs Hume’s procedure, identifies the thinkers he may have had in mind, and argues that his exposé of the hidden passage from description to norm involves precisely the sort of textual “violence” Derrida attributes to concealed interpretive acts.¹

Hume’s Surface Argument

At face value, Hume performs a meticulous audit of moral treatises. He follows the reasoning “for some time in the ordinary way,” notes theological or empirical premises, and then encounters an abrupt normative conclusion (Hume, 1739/2000, p. 302). His explicit complaint is logical: no writer supplies the missing premise required to transform facts into obligations. Framed as a plea for “caution,” the criticism projects an ethos of intellectual honesty rather than iconoclasm.

The Silent Transition

Hume’s surprise, however, is more than pedantic. The shift occurs “imperceptibly,” indicating not mere oversight but structural necessity. By isolating this unmarked hinge, he exposes what Derrida would later call an aporía—a point where argument demands what it cannot legitimately deliver. The moralist needs the ought to complete the system yet must pretend it flows organically from descriptive material. Hume pinpoints the instant when rhetoric masquerades as inference, revealing an unstated dependency that fractures the discourse’s coherence.

The significance of this overlooked hinge becomes clearer once we consider how Derrida characterizes the covert imposition of normative structures as a form of interpretive force.

The Violence of Normative Smuggling

Derrida frequently labels such covert moves violence: an imposition that erases its own trace so as to appear self‑evident (Derrida, 1976, p. 163). When a writer sneaks prescriptive content into factual exposition, the text enforces a norm while disavowing its contingent origin. Because the leap is camouflaged as logical necessity, the reader is quietly coerced into assent. Hume’s language—“smuggle” would not be inappropriate—anticipates Derrida’s diagnosis of discursive force that naturalises hierarchy. By detecting the intrusion, Hume not only identifies a logical failure but also unmasks a power play: the author asserts moral authority by concealing the interpretive decision that grounds it.²

Parallels with Derrida’s Double Reading

Derrida’s double reading unfolds in two phases: first, a faithful reconstruction of the text’s self‑presentation; second, a critical traversal that uncovers the tension undermining that presentation (Bradley, 2008). Hume’s technique mirrors this choreography. Initially he “proceeds” alongside the philosopher, reconstructing the chain of empirical or theological propositions. Only after that loyal engagement does he announce the rupture—the surreptitious arrival of ought. His practice therefore stages both compliance and interruption. While Hume’s aim is not to celebrate undecidability but to demand argumentative transparency, the form of his inquiry foreshadows Derrida’s insistence that every system harbours a fault line that opens it to alternative readings.

Derrida also highlights the exorbitant element—the supplement introduced as external yet shown to be indispensable (Derrida, 1976, p. 154). The prescriptive ought in moral reasoning functions exactly as such a supplement. It appears marginal, almost decorative, but without it the edifice of normativity collapses. Hume’s “grain” thus cracks the façade, demonstrating how the supplemental term simultaneously sustains and destabilises moral discourse.

Possible Targets: Natural‑Law Moralists

Although Hume names no culprits, context suggests that natural‑law theorists—including Aquinas, Pufendorf, and perhaps Francis Hutcheson—stand behind his complaint. Their treatises commonly derive duties from human nature or divine reason.³ By spotlighting the silent hinge between anthropological observation and ethical imperative, Hume implicitly challenges the theological‑rationalist project that dominated eighteenth‑century Britain and Europe. His critique therefore functions not merely as methodological counsel but as polemic against prevailing moral metaphysics.

Conclusion

Hume’s concise paragraph operates on two registers. Overtly, it offers a modest recommendation: philosophers should supply the missing link between is and ought. Latently, it enacts a more radical gesture by exposing the fragility of any discourse that hides its normative commitments behind descriptive façades. Viewed through Derrida’s lens of double reading, the passage emerges as a proto‑deconstructive moment that uncovers the violence implicit in rhetorical sleight‑of‑hand. By attending both to the letter of moral arguments and to their invisible pivots, Hume anticipates a critical practice that would only later receive a name but was already, as he might say, “of the last consequence.”

Endnotes

1. Derrida uses violence not in the physical sense but to denote the forcible ordering of meaning (Derrida, 1976).
2. On symbolic violence see Bourdieu’s later sociological usage, which shares this emphasis on invisible coercion.
3. See Moore (1903/1993) for a related critique of deriving ethics from nature, later termed the naturalistic fallacy.

References

Bradley, A. (2008). Derrida’s double reading and literary criticism. Journal of Post‑Structural Studies, 12(2), 45–62.

Derrida, J. (1976). Of grammatology (G. C. Spivak, Trans.). Johns Hopkins University Press. (Original work published 1967)

Hume, D. (1739/2000). A treatise of human nature (D. F. Norton & M. J. Norton, Eds.). Oxford University Press.

Bourdieu, P. (1991). Language and symbolic power (J. B. Thompson, Ed.; G. Raymond & M. Adamson, Trans.). Harvard University Press. (Original work published 1982)

Moore, G. E. (1903/1993). Principia ethica. Cambridge University Press.