The Thinkable and the Unthinkable I: How Arkady Plotnitsky’s Complementarity Intersects with Deconstruction, Psychoanalysis, and Complexity

The intersection of quantum mechanics, deconstruction, and psychoanalysis is not an obvious one. Yet Arkady Plotnitsky’s work demonstrates how these seemingly distinct fields share a fundamental concern with the limits of knowledge—what can be thought and what remains unthinkable. In his paper "The Thinkable and the Unthinkable in Psychoanalysis and Philosophy, From Sophocles to Freud to Derrida" (The Undecidable Unconscious: A Journal of Deconstruction and Psychoanalysis, 2014), Plotnitsky argues that psychoanalysis and deconstruction engage with an irreducibly unthinkable dimension, just as quantum physics confronts the impossibility of fully conceptualizing matter at its most fundamental level.

On the surface, quantum theory, with its abstract mathematics and counterintuitive principles, might appear to be worlds apart from the language-centered concerns of deconstruction or the clinical and theoretical concerns of psychoanalysis. However, Plotnitsky shows that each domain confronts a kind of limit—a threshold beyond which the potential for comprehension and representation breaks down. In other words, each domain grapples with aspects of reality that refuse totalization. This blog post explores how Plotnitsky’s concept of complementarity, which has its roots in Bohr’s quantum mechanics and which Plotnitsky aligns with aspects of Derrida’s deconstruction, resonates with ongoing discussions in complexity theory, psychoanalysis, and philosophy of mind. At stake is the question of whether human intelligence, the unconscious, and symbolic structures can be fully captured in rational models or whether they resist finalization—remaining open, incomplete, and fundamentally non-classical in their structure.

1. Plotnitsky’s Complementarity and the Limits of Thought

Plotnitsky develops complementarity from Niels Bohr’s quantum mechanics, where wave-particle duality presents a paradox: electrons and photons exhibit mutually exclusive behaviors depending on how they are observed. Rather than resolving this contradiction, Bohr argued that both descriptions are necessary but irreconcilable. Plotnitsky extends this insight into the realm of philosophy and psychoanalysis, where concepts such as the unconscious, différance, and non-classical ontology similarly require complementary yet irreconcilable perspectives.

• The Unthinkable in Psychoanalysis: Freud’s das Unbewusste (the unconscious) represents the unknown, but not necessarily the unthinkable (see the addendum below). While the unconscious consists of thoughts, desires, and drives that remain inaccessible to immediate awareness, Freud did not claim that these contents were beyond representation or analysis. Rather, they manifest indirectly—through dreams, parapraxes (Freudian slips), symptoms, and symbolic formations—and can be deciphered through psychoanalytic interpretation.

  This distinguishes Freud’s unconscious from later non-classical epistemologies, such as those developed by Lacan, Derrida, and Plotnitsky, which emphasize a more radical unthinkability. Lacan’s Real, for instance, marks a domain of absolute ontological impossibility, a space beyond symbolization where something resists incorporation into thought. Derrida’s différance similarly ruptures the possibility of full presence and meaning, suggesting that the unconscious is not merely repressed but structurally ungraspable.

  Plotnitsky, drawing from Bohr’s complementarity in quantum mechanics, extends this notion of the unthinkable to psychoanalysis and philosophy. If Bohr demonstrated that certain quantum phenomena cannot be represented within a single conceptual framework, Plotnitsky suggests that the unconscious, too, operates within an epistemological limit where thought reaches its breaking point.

  Thus, while Freud’s unconscious remains hidden yet analyzable, later theoretical developments—including those in quantum epistemology, deconstruction, and complexity theory—suggest that certain dimensions of subjectivity, language, and cognition cannot simply be uncovered, but instead must be understood as irreducibly beyond thought. In this sense, Plotnitsky’s work aligns more with a psychoanalysis of the unthinkable than with Freud’s more reconstructive project of deciphering the unknown.. However, Plotnitsky suggests that at its deepest level, the unconscious moves toward what he calls non-classical ontology—a space where concepts like Being or thought become fundamentally inapplicable. In other words, psychoanalysis gradually reveals not just hidden or repressed contents, but a structural limit to how far rational or classical thinking can go in conceptualizing psychic phenomena.

  
  

• Deconstruction and the Unthinkable: Derrida’s concept of différance is similarly unthinkable in the classical sense. It is neither a thing nor an absence but a constitutive delay that makes meaning possible while ensuring that meaning is never fully present. This aligns with Plotnitsky’s claim that psychoanalysis and deconstruction encounter the same epistemological crisis as quantum physics—namely, the inability to fully capture reality through stable concepts.

  
  

• Non-Classical Epistemology: Just as Bohr rejected classical determinism in physics, Plotnitsky argues that Freud and Derrida reject the idea that the mind, language, or meaning can be fully systematized. This is a direct challenge to traditional analytic philosophy and behavioral psychology, which often assume that intelligence and cognition can be rationally described, modeled, or computed.

The upshot is that at the limits of knowledge—whether in quantum mechanics, psychoanalysis, or deconstruction—we encounter something structurally “unthinkable” that nonetheless shapes our reality. This is where complexity science and psychoanalysis share a deep resonance: both recognize irreducible indeterminacies within their respective fields. In psychoanalysis, we might understand this indeterminacy as the Real that escapes symbolic capture, while in quantum mechanics, it appears in the form of probabilities that resist definite classical states.

2. Overlaps with Complexity, Psychoanalysis, and Deconstruction

Plotnitsky’s perspective lays out a fruitful landscape for comparison. Complexity theory, often associated with fields like dynamic systems, chaos theory, and network analysis, underscores how certain phenomena evade straightforward, linear explanation. Psychoanalysis similarly describes a psychic economy that is non-linear and fraught with hidden causes. Deconstruction, for its part, interrogates language itself, revealing how deferred meaning and contextual shifts unravel any attempt at final interpretation. Let us see how these overlaps unfold in more detail.

a) The Incompleteness of Knowledge

One of the most striking connections between Plotnitsky’s work and complexity science is the idea of ontological incompleteness. Plotnitsky’s non-classical ontology states that the ultimate nature of thought, matter, or Being is systematically beyond our grasp.

• Quantum Mechanics & Gödelian Incompleteness: Gödel’s incompleteness theorems and Turing’s halting problem reveal intrinsic limits within formal logical systems—limits that are structurally similar to the epistemic gaps in quantum physics and psychoanalysis. Where quantum physics reaches a limit in measurement and representation, Gödel’s logic and Turing’s computation show analogous limits in mathematics and computer science.

• Psychoanalysis: Freud initially believed that the unconscious could be systematically mapped, but as psychoanalysis evolved, figures like Lacan and Derrida pushed the idea that the unconscious operates at the level of the unthinkable—it is not just unknown, but unknowable in principle. This unknowable core challenges a purely systematic or classical view of the psyche.

• Deconstruction: Derrida’s différance similarly suggests that meaning is always deferred, preventing a final grounding of knowledge. In Plotnitsky’s terms, this is a non-classical epistemology, where meaning functions like a quantum phenomenon—always shifting based on context, never fully present.

This shared concern with incompleteness suggests that attempts to systematize human intelligence or consciousness into strict rational models (such as AI cognition models or neuro-reductionist frameworks) will always encounter structural limits that evade reduction. In a sense, Plotnitsky’s perspective invites us to see that all these different disciplines—physics, philosophy, and psychoanalysis—have been grappling with the same core issue: there is a dimension of reality or mind that cannot be pinned down by classical approaches.

b) Complementarity in Mind and Meaning

Another major overlap is the idea of complementarity in psychology and deconstruction.

• In Psychoanalysis: Freud’s model of the split subject suggests that our thoughts and desires are structured by complementary but contradictory forces (e.g., conscious/unconscious, repression/expression). This resonates with quantum complementarity, where the subject of psychoanalysis is never fully one thing or the other but exists in a paradoxical interplay of presence and absence. In such a framework, to observe or articulate one dimension of the subject is to lose grasp of the other, much as measuring the particle aspect loses the wave aspect in quantum experiments.

• In Deconstruction: Derrida’s notion that meaning is never fully “here” but always deferred can be understood in light of quantum superposition—where a system exists in multiple states until it is observed. Derrida and Plotnitsky both highlight the non-classical nature of signification, where meaning is relational, unstable, and undecidable.

• In Complexity Science: Much like psychoanalysis and deconstruction, complex systems do not resolve into a singular mode of explanation. The interaction of multiple forces—feedback loops, emergent behaviors, unpredictability—means that any attempt to construct a totalizing “rational-calculable” model of intelligence will always be incomplete.

The implication here is profound: if psychoanalysis and deconstruction share a similar structure with quantum mechanics and complexity science, then attempts to create a fully computable model of human intelligence (such as AI-based theories of mind) are fundamentally flawed. The mind is not a machine because intelligence is entangled with the unthinkable—it cannot be reduced to a set of formal rules or algorithms.

It is important to note that this is not a reductive analogy, such that psychoanalysis is “just like quantum physics.” Rather, the claim is more subtle: each domain independently confronts a mode of irreducibility that challenges classical thinking.

3. Toward an Anti-Epistemology of Mind

If Plotnitsky’s ideas are correct, we are led toward something like an anti-epistemology—a stance that does not seek to conquer or resolve the unthinkable, but rather to recognize it as constitutive. Rather than treat this dimension as a problem to be solved, we might think of it as the productive core of creativity, ethics, and genuine thought.

a) Why This Challenges Analytic Philosophy and Cognitive Science

If Plotnitsky is correct, analytic philosophy and mainstream cognitive science operate under a classical ontology that assumes thought can be formalized, modeled, and ultimately systematized. However, if intelligence operates according to non-classical principles, then these models are structurally incapable of capturing the essence of consciousness.

• Kurzweil’s Singularity is a Myth: If human intelligence cannot be fully represented in classical models, then the comparison between AI and human cognition collapses. Kurzweil’s singularity assumes that intelligence is computable, but Plotnitsky’s work suggests that human thought includes an “unthinkable” dimension that AI can never replicate.

• The Limits of Behavioral Science: Behavioral psychology operates on predictable models of cognition, but Plotnitsky’s insights show that cognition includes fundamental unpredictabilities. Much like quantum measurement, the moment you attempt to formalize thought, it changes in response.

As a result, from this anti-epistemological point of view, the project of fully modeling the mind—be it through neural nets, symbolic logic, or behaviorist frameworks—will inevitably reach a horizon beyond which it cannot venture.

b) Ethics of the Unthinkable

Plotnitsky’s insights also have ethical implications. If thought is fundamentally open-ended and non-classical, then any system that attempts to totalize human intelligence risks imposing artificial constraints on subjectivity. Recognizing the irreducibility of mind leads to an ethics of incompleteness—an acknowledgment that true care, creativity, and intelligence emerge precisely where systematization fails.

This ethics is not simply a celebration of ignorance; it is an understanding that, at the borders of our theories and our languages, we encounter an “unthinkable” that calls for humility, openness, and respect for otherness. Whether we are talking about quantum phenomena or the singular experience of another subject, an ethical stance would refrain from forcing closure or total explanation.

Conclusion

Plotnitsky’s complementarity bridges quantum physics, psychoanalysis, and deconstruction in a way that profoundly challenges our understanding of intelligence, cognition, and meaning. By recognizing non-classical epistemologies, we see that human intelligence is irreducibly complex, entangled with the unthinkable, and fundamentally beyond mechanization.

This has direct implications for AI research, philosophy of mind, and psychoanalytic theory, as it suggests that any attempt to fully formalize intelligence will always leave something out—something unthinkable, yet foundational to what makes us human. Indeed, we find a unique convergence among these fields: quantum mechanics with its wave-particle complementarity, psychoanalysis with its unthinkable unconscious, and deconstruction with its deferred and destabilized meaning. Each domain confronts a space of irreducible complexity or “unthinkability” where no single perspective can fully dominate or explain.

Ultimately, Plotnitsky’s work invites us to befriend these limits rather than see them as mere obstacles to be conquered. They are, in a real sense, the very conditions that foster genuine thought, creativity, and ethical engagement. We stand at the threshold of the thinkable and unthinkable in multiple domains—physics, mind, and language—and if we follow Plotnitsky’s clues, we might discover that it is precisely in these liminal zones of indeterminacy that the deepest insights about human (and perhaps non-human) reality reside.

This exploration of Plotnitsky’s complementarity and its resonance with complexity, psychoanalysis, and deconstruction underscores that the very limits of thought—those points where knowledge reaches its breaking edge—are not obstacles to be overcome but the conditions that sustain these fields. Rather than seeking to eliminate paradox or impose closure, embracing these tensions reveals the ongoing dynamism at the heart of human inquiry, ensuring that meaning, subjectivity, and intelligence remain open, evolving, and resistant to finalization.

Addendum: Freud’s das Unbewusste—The Unknown, Not the Unthinkable?

A key point of resonance between Plotnitsky’s notion of complementarity, psychoanalysis, and deconstruction lies in the distinction between the unknown and the unthinkable. Plotnitsky, following Bohr’s epistemology of quantum mechanics, argues that scientific and philosophical thought often runs up against irreducible epistemic limits, where certain phenomena remain fundamentally beyond conceptualization. This notion of the unthinkable echoes Derrida’s différance and Lacan’s Real, both of which mark limits where representation collapses. But how does Freud’s concept of the unconscious (das Unbewusste) fit into this framework?

Freud’s das Unbewusste is often described as the unknown, but does it qualify as the unthinkable? The term itself, which literally means “the unconscious” in German, derives from un- (not) + bewusst (conscious, aware), indicating something that is not within conscious awareness but not necessarily something unthinkable in a deeper ontological sense. Unlike Plotnitsky’s quantum epistemology or Derrida’s critique of presence, Freud’s unconscious is not beyond thought altogether—it is merely repressed, concealed, or distorted, yet still accessible through dreams, symptoms, and psychoanalytic interpretation.

In this sense, Freud’s unconscious aligns with Plotnitsky’s unknown but thinkable domain rather than the radically unthinkable realms found in quantum mechanics or deconstruction. Freud believed that the unconscious operated under different logical principles (primary process thinking) but could still be analyzed, symbolized, and re-integrated into conscious thought. This is why he often described it as “knowable through its effects”, much like quantum physicists infer the behavior of particles through indirect traces rather than direct observation.

However, later psychoanalytic and philosophical developments—particularly in Lacan, Derrida, and Plotnitsky himself—push Freud’s concept toward a more non-classical formulation. Lacan’s Real introduces a domain of absolute impossibility, where certain aspects of subjectivity cannot be symbolized or thought at all. Derrida’s différance similarly suggests that meaning is not just deferred but structurally absent, leaving gaps that cannot be closed. Plotnitsky, working through both quantum epistemology and Derridean deconstruction, suggests that psychoanalysis too must ultimately reckon with an unthinkable dimension—something not merely hidden but systematically beyond cognition.

Thus, if Freud’s unconscious is the unknown but ultimately decipherable, the later trajectory of psychoanalysis and deconstruction suggests something closer to the unthinkable—a field of effects without a fully graspable cause, a remainder that defies formalization. In this light, Plotnitsky’s non-classical epistemology challenges psychoanalysis to move beyond Freud’s rational reconstruction of the unconscious toward something more akin to quantum uncertainty—a domain where meaning, subjectivity, and thought itself break down at their most fundamental level.