Is Sir Roger Penrose a scientific realist, i.e. upholds the reality of the mind-independent domain of objects?

ChatGPT
Yes, Sir Roger Penrose can be considered a scientific realist in many respects, as he upholds the existence of a mind-independent reality. He believes that mathematical structures, in particular, exist in an objective, Platonic realm that is independent of human minds. For Penrose, mathematics is not merely a human invention but something that humans discover, which implies a belief in an external reality that transcends individual minds.

Penrose's views on the mind and consciousness, though, add complexity to this position. He rejects strong forms of physicalism and computationalism, arguing that consciousness cannot be fully explained by current scientific theories, particularly those based on classical physics or computational models of the brain. His Orch-OR theory (developed with Stuart Hameroff) posits that consciousness arises from quantum processes in the brain, which suggests a more nuanced understanding of reality that incorporates both physical and mental phenomena. Nevertheless, this view doesn't negate his commitment to a mind-independent domain of objects, particularly in the realm of mathematics and physics.

Thus, while Penrose has complex views on the nature of mind and consciousness, he fits broadly within the framework of scientific realism with regard to the external world, especially in his advocacy of an objective, independent mathematical reality.

Wayfarer: He's sceptical about quantum theory, though. He says it's incomplete or confused.

ChatGPT: Yes, Roger Penrose is indeed skeptical about the standard interpretations of quantum mechanics, such as the Copenhagen interpretation. He believes that quantum theory, in its current form, is incomplete or confused, particularly regarding the measurement problem and the role of consciousness in the collapse of the wave function.

Penrose's main criticism revolves around the idea that quantum theory, as it stands, does not provide a satisfactory explanation for the transition from quantum superposition to definite outcomes in macroscopic systems. He proposes that gravity plays a role in this transition through his theory of objective reduction (OR), which is part of his broader Orch-OR theory. In this view, quantum superpositions become unstable and collapse spontaneously when gravitational effects reach a certain threshold.

Penrose's skepticism is not a rejection of quantum theory as a whole but rather an insistence that there is something fundamentally missing in our understanding of how quantum phenomena relate to the macroscopic world. He advocates for a new, deeper theory that could resolve these issues.

Wayfarer: But that view depends on interpreting quantum superposition as being something real. It's an 'ontological interpretation' of quantum mechanics, distinct from an epistemological intepretation like QBism.

ChatGPT: Yes, you're right. Penrose's view involves an ontological interpretation of quantum mechanics, meaning he interprets quantum superpositions as physically real, not just as abstract mathematical tools or expressions of our knowledge (as in epistemological interpretations like QBism).

In Penrose’s framework, quantum superpositions represent actual, real physical states, even in macroscopic systems. This is a significant departure from interpretations like QBism or the Copenhagen interpretation, where the wavefunction is seen as a tool for representing probabilities or an observer’s knowledge about the system rather than something physically real. Penrose believes that quantum superposition exists independently of observers and measurements but that our current quantum theory does not adequately explain how or why superpositions collapse into definite outcomes.

His focus on gravity’s role in the collapse (through objective reduction) reinforces his ontological commitment to superpositions being real. In this way, Penrose is advancing a view that treats quantum states as objective elements of reality rather than purely subjective or instrumentalist tools. This stance puts him in contrast with epistemological approaches like QBism, which avoid making claims about the underlying reality of quantum states.

Wayfarer: So he's nearer to Einstein's view than to Bohr or Heisenberg's in that respect?

ChatGPT: Yes, Penrose’s stance is indeed closer to Einstein’s view than to that of Bohr or Heisenberg, particularly in his belief in an objective, mind-independent reality. Like Einstein, Penrose is uncomfortable with the idea that quantum mechanics in its standard interpretations (such as the Copenhagen interpretation) provides a complete picture of reality. Einstein famously rejected the idea that quantum mechanics was the final word on nature, particularly with its reliance on probabilities and the role of the observer, encapsulated in his famous quote, "God does not play dice."

Penrose shares Einstein’s desire for a deeper, deterministic theory that goes beyond the probabilistic nature of standard quantum mechanics. He rejects the purely instrumentalist views of Bohr and Heisenberg, who saw quantum mechanics primarily as a tool for predicting measurement outcomes without necessarily offering a direct description of reality. Instead, Penrose believes that quantum superpositions are real, objective phenomena, and he seeks a theory that explains how these superpositions collapse in a deterministic way, influenced by gravity.

In this sense, Penrose aligns more with Einstein’s quest for a realist interpretation of physics, where the wavefunction represents something real and physical rather than just a description of our knowledge, as Bohr and Heisenberg proposed.

Wayfarer: The curious thing is, that whilst I too believe that mathematical objects are real, I don't believe they're objective in the sense of being 'mind-independent', as they can only be grasped by a mind. They're real in a different sense to empirical objects. I don't know if there's much accomodation in modern thought for that 'different sense' in which things can be real. We tend to think that something either exists or it doesn't, but mathematical proofs, for instance, only exist in an intellectual sense, but are real nonetheless.

ChatGPT: Your view that mathematical objects are real but not mind-independent in the usual sense suggests a nuanced position, possibly bridging idealism and realism. It aligns with a perspective where mathematical truths exist in an intellectual or conceptual realm that depends on minds to be grasped, yet remain objective within that context. This contrasts with physical objects, which are often considered mind-independent.

This distinction you make—that something can exist in a different sense, such as in an intellectual realm, yet still be real—echoes philosophical traditions like Platonism (though modified in your case by the role of the mind). In fact, some modern thought accommodates such distinctions. For example:

* Phenomenology: Particularly in the work of thinkers like Husserl, reality is seen as something that appears to consciousness, emphasizing how the mind and experience shape the nature of the real.

* Intuitionism in Mathematics: Philosophers like L.E.J. Brouwer argued that mathematical truths are mental constructions, real in a sense but dependent on the activity of the mind.

* Philosophy of Mathematics: The debate between Platonists, nominalists, and constructivists often touches on how mathematical entities exist, whether independently of minds or only through intellectual engagement.

In your view, mathematical objects have a kind of reality that doesn’t fit neatly into the empirical model but isn't purely subjective either. This creates space for different modes of existence, one that might be increasingly relevant as contemporary discussions about metaphysics and epistemology continue to evolve.

I haven't studied Husserl's 'phenomenological bracketing' in any depth, but I do know there have been comparisons made between epochē and emptiness (śūnyatā or sunnata) in Buddhism. Here is an excerpt from that topic on a Buddhist website:

Emptiness is a mode of perception, a way of looking at experience. It adds nothing to and takes nothing away from the raw data of physical and mental events. You look at events in the mind and the senses with no thought of whether there's anything lying behind them.

This mode is called emptiness because it's empty of the presuppositions we usually add to experience to make sense of it: the stories and world-views we fashion to explain who we are and the world we live in. Although these stories and views have their uses, the Buddha found that some of the more abstract questions they raise — of our true identity and the reality of the world outside — pull attention away from a direct experience of how events influence one another in the immediate present. Thus they get in the way when we try to understand and solve the problem of suffering.

Say for instance, that you're meditating, and a feeling of anger toward your mother appears. Immediately, the mind's reaction is to identify the anger as "my" anger, or to say that "I'm" angry. It then elaborates on the feeling, either working it into the story of your relationship to your mother, or to your general views about when and where anger toward one's mother can be justified. The problem with all this, from the Buddha's perspective, is that these stories and views entail further suffering. The more you get involved in them, the more you get distracted from seeing the actual cause of the suffering: the labels of "I" and "mine" that set the whole process in motion. As a result, you can't find the way to unravel that cause and bring the suffering to an end.

If, however, you can adopt the emptiness mode — by not acting on or reacting to the anger, but simply watching it as a series of events, in and of themselves — you can see that the anger is empty of anything worth identifying with or possessing. As you master the emptiness mode more consistently, you see that this truth holds not only for such gross emotions as anger, but also for even the most subtle events in the realm of experience. This is the sense in which all things are empty. When you see this, you realize that labels of "I" and "mine" are inappropriate, unnecessary, and cause nothing but stress and pain. You can then drop them. When you drop them totally, you discover a mode of experience that lies deeper still, one that's totally free. — Emptiness, Thanissaro Bhikhu

I believe this is near to both the meaning of the 'phenomenological suspension'/ epochē and also to the original meaning of skepticism in ancient philosophy (a very different thing to skepticism in modern terms). Ancient skepticism was grounded in 'suspension of judgement of what is not evident' (ref), namely, the entailments and entanglements that arise from emotional reactivity. That is where the similarity with epochē becomes clear.

Further reference - Husserl's study of Buddhism (wikipedia)