QUANTUM PHYSICS NEEDS PHILOSOPHY, BUT SHOULDN'T TRUST IT

Now FREE to read

Comrades,

I was invited to speak at a conference dedicated to the work of Lee Smolin in Waterloo (Canada) on June 5 2025:

Lee's Fest: Quantum Gravity and the Nature of Time.

Below, a text of this speech, now FREE to read

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(Picture: Astronomer Copernicus, or Conversations with God by Jan Matejko, 1873)

What am I, a philosopher, doing here, where specialists will debate features of quantum gravity well beyond the scope of my understanding? From its very beginnings, it was clear that quantum mechanics (QM) has earth-shattering implications for our notion of reality. However, although there were speculations here and there, the predominant stance until recently was Copenhagen orthodoxy: “Don’t think, just calculate!” In the last decades, ontological questions have exploded. At the very beginning of his bestselling The Grand Design, Stephen Hawking triumphantly proclaims that “philosophy is dead.” With the latest advances in quantum physics and cosmology, so-called experimental metaphysics has reached its apogee: metaphysical questions about the origins of the universe, the nature of space and time, etc.—which until now were the topic of philosophical speculation—can now be answered through experimental science and thus, in the long term at least, empirically tested. However, things are not as simple as that. Many quantum scientists are now aware that they should be raising proper philosophical questions (for example: What is the nature of quantum waves? Do they form a reality separate from our common material reality, or are they just instruments of calculation?).

Following these debates as an outsider, I noticed that many quantum physicists have taken refuge in esoteric spiritualism or direct subjective idealism. Here is a typical comment: “Do paradoxes like this really echo ancient philosophies like Advaita Vedanta, which say separateness is an illusion and everything is connected? Quantum entanglement reveals particles can remain linked across vast distances, as if part of one indivisible whole.” Even Roger Penrose wrote at some point that “Somehow, our consciousness is the reason the universe is here,” not to mention Zeilinger, who links QM to Tibetan Buddhism. No wonder that many obscurantist philosophers join them in this endeavour—for them, the quantum collapse is an act of free conscious decision.

Lacan knew what he was saying when he claimed that quantum mechanics is the first science that deals with the Real—the Real as distinct from the symbolically constituted reality. The whole point of quantum mechanics is that there is another level of being which obeys laws different from our ordinary reality: the Real of quantum waves, of quantum superpositions that collapse into our reality. This level is indeterminate but still deterministic; the probability of a collapse is governed by the very precise Schrödinger equation. At this quantum level, our standard notion of time and space as universal containers of all reality must also be abandoned.

To interpret this quantum domain as the final refutation of materialism and as proof that reality is spiritual succeeds only if we restrict ourselves to the classic deterministic notion of reality—small material particles jumping around in all-encompassing space and time. Furthermore, the role of observation is far more complex: experiments confirm that a collapse occurs when a quantum process is "observed" by a measuring device, even with no conscious awareness whatsoever.

Those who claim there is no reality outside consciousness dismiss as a pseudo-problem the most philosophically intriguing aspect of quantum mechanics: the exact ontological nature of quantum waves, their collapse, and the retroactive causation implied by such events. So you, quantum scientists, need philosophy, but you should not trust philosophers who appropriate your work for obscurantist purposes.

Here enter people like Lee and the entire gang around him, from Francesca Vidotto and Carlo Rovelli to Julian Barbour and Sean Carroll. Like me, they remain materialists, although they are well aware that the notion of materialism has to be radically rethought after quantum physics. So what does materialism mean here? Not that the ultimate reality is empty space with small elements floating in it, but something much more interesting. Einstein’s full determinism relies on a religious foundation—he wrote: "Raffiniert ist der Herrgott, aber boshaft ist er nicht." (God is subtle, but he is not intentionally deceiving us). Although Einstein repeatedly pointed out that he didn’t believe in a personal god, he proclaimed himself deeply religious: "I believe in Spinoza’s God, who reveals himself in the harmony of all that exists.” In this sense, for him, religion and science necessarily coexist: science itself is sustained by the deep faith that our universe is marvellously arranged in a harmony that pervades all that exists. I think it is this very belief which has been dealt a mortal blow by quantum mechanics. For me, quantum mechanics implies an inconsistent, plural world not grounded in any big foundation, even if this foundation is the Void itself.

The basic premise of QM is that reality is not what we experience as our well-known external world. The theological implications of this premise are of special interest: “If God collapses the wave functions of large things to reality by His observation, quantum experiments indicate that He is not observing the small.” The ontological cheating with virtual particles (an electron can create a proton and thereby violate the principle of constant energy, on condition that it reabsorbs it before its environs ‘take note’ of the discrepancy) is a way to cheat God himself, the ultimate agency of taking note of everything that goes on: God himself doesn’t control the quantum processes; therein resides the atheist lesson of quantum physics. Einstein was right with his famous claim, “God doesn’t cheat”—what he forgot to add is that God himself can be cheated.

Our predominant approach is that our knowledge is always, by definition, limited, and this limitation appears when we arrive at inconsistent claims or results. In such cases, our conclusion is that inconsistency signals the limitation of our knowledge—there must be some unknown hidden variables that we missed. However, as we all know, in QM the situation can be the exact opposite—let me just mention the simplest case, the wave-particle duality. Particles such as electrons and photons exhibit both wave-like and particle-like properties, depending on whether they are being observed or not. The question “But what is really an electron in itself?” is thus meaningless; the electron is this very duality—there is nothing beyond. So what appears as an epistemic obstacle is turned around into a positive ontic feature.

Similar cases abound in QM and—surprise—in Marxism. Just recall the well-known Theodor Adorno’s analysis of the antagonistic character of the notion of society: at first glance, the split between the two notions of society (the Anglo-Saxon individualistic-nominalistic notion, which emerges through the interaction of individuals, and the Durkheimian organicist notion of society as a totality that preexists individuals) seems irreducible. We seem to be dealing with a true Kantian antinomy, which cannot be resolved via a higher synthesis and which elevates society into an inaccessible Thing-in-itself. However, one should merely take note of how this radical antinomy, which seems to preclude our access to the Thing, ALREADY IS THE THING ITSELF—the essential feature of today’s society IS the irreconcilable antagonism between Totality and the individual. What this means is that, ultimately, the status of the Real is purely parallactic and, as such, non-substantial: it has no substantial density in itself; it is just a gap between two points of perspective, perceptible only in the shift from one to the other.

This is why, as a Hegelian philosopher, I am so fascinated by quantum mechanics, despite the fact that they are definitely strange bedfellows—already the substantives seem incompatible: ‘dialectics’ versus ‘mechanics’… But what we find in quantum physics is something that is usually considered an exclusive feature of the symbolic universe: a self-reflective move of including the observer’s own position into the series of observed phenomena. Recall Hegel’s famous infinite judgment, “Spirit is a bone”—how does it work? Instead of arguing (from the safe distance of an observer) that spirit cannot be reduced to a bone, it begins by endorsing the claim “spirit is a bone.” Our reaction to this statement is one of shock; we experience this claim as blatant nonsense… but it is only through experiencing the nonsense/negativity of this statement that we arrive at Spirit, because “spirit” is just such a self-relating negativity which encompasses me in my subjective stance.

QM talks a lot about loops, and I think there is a fundamental loop that characterizes the human subject. We humans dwell in language, but we are never fully at home in language. The positive spin of a failure can be best illustrated by the loop of symbolic representation: a subject endeavors to adequately express or represent itself, this representation fails, and the subject IS the result of this failure. Recall what one might be tempted to call the “Hugh Grant paradox” (referring to the famous scene from the movie Four Weddings and a Funeral): the hero tries to articulate his love to the beloved, he gets caught in stumbling and confused repetitions, and it is this very failure to deliver his message of love in a perfect way that bears witness to its authenticity… It is obvious that Grant’s individuality expresses itself precisely through these failures: if he were to declare his love in a perfect and smooth way, we would get a robot-like recitation. The loop here is not the simple organic co-dependence of a body and its parts but a leap mediated by a failure. An impulse fails to fully actualize itself, and this impulse retroactively emerges from this failure.

When I asked Carlo Rovelli a nasty question at a recent debate in Hay-on-Wye, I ironically characterized myself as a “Stalinist with a human face”; Carlo immediately snapped back: “I am a Leninist with an ugly face.” (His Leninist stance was perfectly rendered in the title of his opening intervention at this conference: “One of us would be superfluous”—so it is not just a big friendly dialogue; there are (theoretical) liquidations…) This is what I will do now: while generally I fully support Lee’s project, I will now address to Lee two observations that express my Leninist confusion. So my first question to Lee is: he claims that “I am convinced that quantum mechanics is not a final theory. I believe this because I have never encountered an interpretation of the present formulation of quantum mechanics that makes sense to me.” If his project to move beyond both Einstein’s relativity and QM succeeds, what will happen to this feature of QM that most fascinates me—this transposition of epistemic into ontic limitation? Is the gap between gravity and quantum mechanics also its own solution? No, I think this is a much stronger conceptual difference: the two, gravity (as articulated in Einstein’s general relativity theory) and QM, belong to incompatible conceptual spaces. This is why Lee is right: quantum gravity will compel us to move beyond both spaces; it is not a synthesis of the two.

My second question concerns the social and political implications that Lee draws from his ontological vision of the primacy of time—the vision of openness and democracy that he shares with Roberto Unger. Lee advocates “principles for an open future,” which he claims underlie the work of both healthy scientific communities and democratic societies. Here is a quote from his Time Reborn:

(1) When rational argument from public evidence suffices to decide a question, it must be considered to be so decided.
(2) When rational argument from public evidence does not suffice to decide a question, the community must encourage a diverse range of viewpoints and hypotheses consistent with a good-faith attempt to develop convincing public evidence.

If loops in quantum gravity are more basic than spacetime, in what sense is time then primordial? The primacy of time means that the past itself is open towards the future; it is not simply “what really happened,” but is full of cracks and alternate possibilities—the past is also what failed to happen, what was crushed so that “what really happened” could have occurred. It is at this point that we should avoid the fatal trap of conceiving this “openness” of reality in the sense of a single temporal reality that is open towards the future and solicits incessant, gradual progress.

No wonder that Smolin, an opponent of block-universe theory and advocate of the reality of time, co-wrote a book with Unger whose stance is that of a “radicalized pragmatism,” “the operational ideology of the shortening of the distance between context-preserving and context-transforming activities.” It is thus a program of permanent revolution—however, a program so conceived that the word ‘revolution’ is robbed of all romantic otherworldliness and reconciled to the everydayness of life as it is. Here, we see an example of how a socio-political vision of gradual progress, of the permanent self-transformation of humans, echoes a fundamental ontological vision that appears to me out of touch with the ontology implied by QM. Does QM not imply a universe in which there is no global progress, in which every progress is localized and may appear a catastrophe from a different standpoint? The most obvious case: who knows what the final outcome of AI will be? How will a direct link between our flow of thoughts and a digital network affect our humanity? Is not the lesson of the twentieth century that the dream of a more just society can turn into hell on earth?

The space for a dialogue with science is opened up by the fact that the specifically human dimension of dwelling in language and engaging in symbolic exchanges does not take place due to the intervention of some higher spiritual force standing above the mere reproduction of life; it happens within life itself, as its self-negation, which occurs due to some totally contingent anomaly, through the exaptation of what was in itself a misfortune. Our entire spiritual edifice comes second; it is a reaction to this disturbance, an attempt to cope with it. The ultimate irony of the “becoming-human of apes” is that the reason was utterly contingent and without any meaning—in all probability, some pathological neuronal short-circuit, a meaningless malfunction. At the organic level, something went wrong: a living being got caught in a repetitive loop of self-destructive acts, and out of this weird accident all of our ethics and the symbolic order itself arose. If, then, science discovers how self-awareness emerged, the result will not be perceived as the clarification of a deep mystery, as an act of bringing out a secret that perhaps should have remained hidden, but as something profoundly disappointing, outrageous in its stupidity.

Does our era, in which our very survival is at stake, not make “radicalized pragmatism” all too flat? Is it not clear that crazy social acts will be needed—acts which will undermine many basic premises of our normal daily life? The point of my two questions to Lee is thus clear: I want to keep alive the madness of QM as well as the madness of politics that alone can save us today. The time of realist pragmatism, which ‘makes sense’ is over; we have to get ready for new emergency states.