Helgoland Rovelli, Erica (cat reading book .TXT) 📖

one further way in which the rethinking of reality suggested by quantum theory helps us dispel the myth of a radical difference between the mental world and the physical world.

The problem of the distance between the mental and physical may seem intuitively clear, but it is difficult to delineate with precision. The mental world has different aspects—meaning, intentionality, values, objectives, ends, emotions, aesthetic and moral senses, mathematical intuition, perception, creativity, consciousness . . . Our mind does many things—it remembers, anticipates, reflects, deduces, is moved, is angered, dreams, hopes, sees; it expresses itself, imagines, creates, recognizes, knows, is self-aware . . . Taken individually, many, if not all, of these human cerebral activities do not seem so far removed from those we can more or less easily reproduce in a sufficiently complex physical device. Is there also anything that cannot emerge from the physics we know?

David Chalmers divided the problem of consciousness into two parts, which he called the “easy” and the “hard” problems.126 The problem that he calls “easy” is anything but: it is how our brain functions. How, that is, it gives rise to the various behaviors that we associate with our mental life. The problem that he calls “hard” is understanding the subjective feeling that accompanies what the brain does.

Chalmers judges it to be plausible that the “easy” problem can be resolved in the context of our current physical conception of the world, but doubts that the same thing can be said for the “hard” one.

He asks us to imagine a “zombie,” namely a machine capable of reproducing any behavior of a human being that can be observed (even with a microscope); a machine indistinguishable from a human being through any external observation, but which lacks subjective experience. “Inside,” as Chalmers puts it, “there is no one.”

The very fact that we can conceive of such possibility shows, for Chalmers, that there is a “something else” that distinguishes a living being from the zombie that could reproduce all its observable characteristics without subjective feelings. This “something else,” according to Chalmers, identifies the difficulty of accounting for subjective experience in terms of our current conception of the physical world. This, for him, is the problem of consciousness.

Neuroscience is making remarkable progress in understanding the functioning of our brain. Most of its workings will probably be clarified sooner or later. Is there anything remaining that will have escaped us, after we have understood this? Chalmers maintains that there will be, because the “hard problem” is not to understand how cerebral activities work; it is to understand how these activities are accompanied by corresponding subjective feelings as they happen. That is, in order to understand the relation between our mental life and the physical world, it is essential to take into account the fact that we describe the physical world from the outside, while our mental activity is experienced in the first person, from within.

But the rethinking of the world suggested by quantum physics, it seems to me, changes the terms of the question. If the world consists of relations, then no description is from outside it. The descriptions of the world are, in the ultimate analysis, all from inside. They are all in the first person. Our perspective on the world, our point of view, being situated inside the world (our “situated self,” as Jenann Ismael beautifully puts it127), is not special: it rests on the same logic on which quantum physics, hence all of physics, is based.

If we imagine the totality of things, we are imagining being outside the universe, looking at it from out there. But there is no “outside” to the totality of things. The external point of view is a point of view that does not exist.128 Every description of the world is from inside it. The externally observed world does not exist; what exists are only internal perspectives on the world which are partial and reflect one another. The world is this reciprocal reflection of perspectives.

Quantum physics shows us that something like this happens already for inanimate things. The set of properties relative to the same object forms a perspective. If we make an abstraction from every perspective, we don’t reconstruct the totality of facts; instead, we find ourselves in a world without facts, because facts are only relative facts. This is the difficulty of the Many Worlds interpretation of quantum mechanics: it describes what an external observer should expect if interacting with the world. But there are no observers external to the world. The interpretation misses the facts of the world.

Thomas Nagel, in a celebrated article, asked the question, “What is it like to be a bat?” He argued that this question is meaningful but escapes natural science.129 The mistake, here, is to assume that physics is the description of things in the third person. On the contrary, the relational perspective shows that physics is always a first-person description of reality, from one perspective.

Ideas on the nature of the mind are often limited to just three alternatives: dualism, according to which the reality of the mind is completely different from that of inanimate things; idealism, according to which material reality only exists in the mind; and naive materialism, according to which all mental phenomena are reducible to the movement of matter. Dualism and idealism are incompatible with the discovery that we sentient beings are a part of nature like any other, and with the overwhelming and ever-increasing evidence that nothing that we observe, including ourselves, violates the natural laws that we know. Naive realism is intuitively difficult to reconcile with subjective experience.

But these are not the only alternatives. If the qualities of an object are born from the interaction with something else, then the distinction between mental and physical phenomena fades considerably. Whether it is the physical variables or what philosophers of the mind call “qualia”—elementary mental phenomena such as “I see red”—both can be thought of as more or less complex natural phenomena.

Subjectivity is not a qualitative leap with respect