Reason at the Limit: A Lesson in Deconstructive Reading

Roy´s Derrida & Foucault. AI image

Introduction: Beyond a Philosophical Dispute

Jacques Derrida’s “Cogito and the History of Madness” (1963) is often remembered primarily as a polemical intervention in Michel Foucault’s History of Madness. Read in that way, the essay appears to revolve around a disagreement concerning Descartes, historical method, and the possibility of giving voice to madness. Yet such a framing risks obscuring what is philosophically most instructive in Derrida’s text.

Rather than functioning merely as a rebuttal, Cogito and the History of Madness operates as a demonstration of deconstructive reading itself. Derrida shows how a foundational philosophical opposition—reason versus madness—depends on language, unsettles its own hierarchy, and ultimately reveals that reason can only constitute itself by passing through what it seeks to exclude. The essay is less concerned with adjudicating historical claims than with exposing how a conceptual structure sustains itself by marginalizing one of its own conditions of possibility.

Framing the Problem: Unreason at the Threshold of Thought

Derrida opens the essay with two epigraphs that immediately destabilize the opposition between reason and madness. Søren Kierkegaard writes that “the instant of decision is madness,” while James Joyce remarks of Ulysses that “a transparent sheet separates it from madness.”¹ These statements do not merely decorate Derrida’s argument; they announce its guiding intuition. What is at stake is not a simple negation of reason, but a limit-condition that emerges precisely when rational mastery falters.

For Kierkegaard, decision becomes possible only when calculation fails, when no option can be justified by reasons alone. Joyce, in turn, suggests that literary invention operates at a perilous proximity to unreason, separated from collapse not by a wall, but by a fragile membrane. Together, these epigraphs suggest that reason, creativity, and responsibility are not secured by excluding madness, but by negotiating a constitutive vulnerability at their core.

This framing is decisive for Derrida’s engagement with Michel Foucault. If the excluded term appears not only as an object of repression but as an internal limit of thought itself, then the philosophical significance of Descartes’ cogito cannot be reduced to a simple act of silencing. The question Derrida poses is therefore not whether madness is historically excluded, but whether reason can ever constitute itself without passing through what threatens to undo it.

Foucault’s Descartes: The Gesture of Exclusion

Derrida’s explicit point of departure is Michel Foucault’s interpretation of Descartes in History of Madness. At the beginning of the book’s second chapter, Foucault describes what he calls a “violent” historical event at the dawn of the classical age: the confinement and silencing of those deemed mad. He then locates a philosophical counterpart to this event in Descartes’ Meditations on First Philosophy.

In the First Meditation, Descartes briefly considers the unreliability of sense perception. He immediately distinguishes this form of doubt from what he describes as insanity, invoking figures who believe themselves to be kings while destitute, or who imagine their bodies to be made of glass. Such people, Descartes writes, are amentes (senseless), and to follow their example would be to become demens.²

On Foucault’s reading, this gesture constitutes a decisive exclusion. Madness is dismissed as unworthy of philosophical consideration, thereby allowing the cogito to establish itself as transparently rational. The Cartesian subject secures certainty not by confronting unreason, but by setting it aside as irrelevant. Philosophy thus mirrors the institutional movement of confinement, the authority of reason is ratified by expelling its other from the space of thought.

Derrida does not deny that Descartes initially brackets empirical madness. What he contests is the claim that this gesture exhausts the role of unreason in the Meditations. To equate the dismissal of madmen with the exclusion of madness as such, Derrida argues, is to overlook what immediately follows in Descartes’ text.

Hyperbolic Doubt and the Descent into Unreason

Derrida’s response proceeds by attending closely to the internal movement of Descartes’ argument. After excluding madness as a pathological condition affecting others, Descartes introduces the hypothesis of dreaming, and then radicalizes doubt further by imagining an evil genius capable of deceiving him in all things, including the most elementary truths of arithmetic.

At this point, doubt exceeds any ordinary conception of insanity. The possibility raised is no longer that others are deluded, but that I myself may be deceived in every judgment I form. The hypothesis of the evil genius does not describe a psychological disorder; it articulates a logical possibility that undermines the very norms of truth and rationality. Hyperbolic doubt, as Derrida emphasizes, is not a safeguard against unreason but a plunge into a more radical destabilization than madness understood as mental illness.

This distinction is decisive. While madness, as Descartes initially presents it, is dismissed as a deviation afflicting others, hyperbolic doubt implicates the thinking subject itself. Reason no longer stands safely opposed to its other; it finds itself exposed to the possibility of total deception.

The Cogito: “Even If I Am Mad”

This moment is central to Derrida’s argument. When Descartes arrives at the cogito—ego cogito, ergo sum—its force does not depend on the exclusion of madness, but on its survival through the most extreme form of doubt. As Derrida famously glosses the argument: “Whether I am mad or not, cogito, sum.”³ The cogito holds even if thought itself is disordered, hallucinatory, or manipulated by a malicious power.

Reason is thus not founded on the absence of madness, but on its internal traversal. The cogito does not guarantee rationality; it guarantees existence at the very moment when rational assurance has collapsed. What appears to be excluded returns, displaced and reinscribed within the very act that claims to secure certainty.

Neither Reversal nor Reconciliation

This rereading unsettles the apparent hierarchy between reason and madness without simply inverting it. Derrida does not claim that madness grounds reason in any positive or substantial sense, nor does he replace rationality with unreason as a privileged term. Rather, he shows that reason can only establish itself by maintaining a constitutive relation to what threatens it.

The excluded term is neither purely external to philosophy nor fully assimilable within it. It marks a limit that reason must approach, negotiate, and partially acknowledge, even as it attempts to draw boundaries around itself. The opposition reason/madness thus proves to be neither stable nor self-sufficient.

Language, History, and the Limits of Access

At this point, the broader deconstructive stakes of Derrida’s essay come into view. Foucault’s project seeks to write a history of madness “itself,” prior to and outside rational discourse. Derrida questions the very possibility of such an undertaking. Any history, he argues, must be articulated in language, concepts, and distinctions that already belong to reason. To speak of exclusion presupposes the logos from which exclusion is said to occur.

This argument does not deny the reality of historical practices of confinement or marginalization. Rather, it questions whether those practices can be rendered intelligible without reinscribing the rational structures through which they are described. Madness cannot be accessed in pure immediacy; it appears only within the differential economy of language.

Conclusion: Deconstruction as a Practice of Reading

The epigraphs from Kierkegaard and Joyce return here with force. Decision, creation, and philosophical foundation all occur at moments when rational calculation falters. The “transparent sheet” separating philosophy, or literature, from madness is thin precisely because language is never fully governed by the order it seeks to impose.

Seen in this light, Cogito and the History of Madness exemplifies deconstructive reading in practice. Derrida does not refute Foucault by appealing to external evidence or by proposing an alternative historical narrative. He works within the text itself, attending to its margins, transitions, and moments of apparent certainty. What emerges is not a final resolution, but a displacement, the opposition between reason and madness can no longer function as a self-grounding foundation.

Whether one ultimately accepts Derrida’s conclusions or sides with Foucault’s historical project, the precision of this intervention remains difficult to dismiss. Derrida shows how a single opposition can be isolated and unsettled until its strongest claims reveal their own limits. Rather than asking what a text declares, deconstruction asks what it must presuppose in order to say what it says. In showing that the cogito remains valid even in madness, Derrida reveals that reason is never self-sufficient. It is constituted at the edge of what it cannot master, and it is precisely there that philosophy begins.

Notes

1. Søren Kierkegaard, Fear and Trembling, trans. Alastair Hannay (London: Penguin, 1985); James Joyce, Selected Letters, ed. Richard Ellmann (New York: Viking Press, 1975).
2. René Descartes, Meditations on First Philosophy, trans. John Cottingham (Cambridge: Cambridge University Press, 1996), First Meditation.
3. Jacques Derrida, “Cogito and the History of Madness,” in Writing and Difference, trans. Alan Bass (Chicago: University of Chicago Press, 1978), 36–37.

Bibliography

Derrida, Jacques. Writing and Difference. Translated by Alan Bass. Chicago: University of Chicago Press, 1978.
———. “Cogito and the History of Madness.”

Descartes, René. Meditations on First Philosophy. Translated by John Cottingham. Cambridge: Cambridge University Press, 1996.

Foucault, Michel. History of Madness. Edited and translated by Jean Khalfa. London: Routledge, 2006.
———. “My Body, This Paper, This Fire.” Appendix to History of Madness.

Joyce, James. Selected Letters. Edited by Richard Ellmann. New York: Viking Press, 1975.

Kierkegaard, Søren. Fear and Trembling. Translated by Alastair Hannay. London: Penguin, 1985.