Conscious(ness) Realist

Publication Reviews and Commentaries
by Larissa Albantakis

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Why consciousness is not like life

Intuitively, it seems obvious what is alive and what is not and yet, defining “life” scientifically has proven quite a challenge. Nevertheless, ever since Schrödinger’s famous book “What is life?”, little doubt remains that science will ultimately explain how life is realized in physical systems.

In consciousness science, those who are weary of the endless debates surrounding the “hard problem” of consciousness (Chalmers, 1995) like to point to life as a model for a reductionist view of consciousness: just as we overcame vitalism to explain life, they say, we will overcome the idea that consciousness is a unique scientific problem and explain it in terms of cognitive functions. In other words, maybe the problem is not as hard as it seems, or maybe it will be dissolved, rather than solved (Seth, 2021).

A recent example of this view can be found in (Doerig et al., 2020): “It is possible that with more data and a more detailed view of the subprocesses of consciousness, the mystery will evaporate, similarly to what happened with the discussion about the ‘nature’ of life. Nowadays biologists understand what life is, but there is no ‘theory of life’ (Machery, 2012). It is the entirety of subprocesses such as homeostasis, reproduction, etc., that differentiates life from non-life.”

However, as Chalmers already pointed out in 1995, comparing life to consciousness is a bad analogy for various reasons, some of which I want to highlight below.

Life is just a bunch of functions; consciousness is a thing in itself

Anil Seth writes: “Once, biochemists doubted that biological mechanisms could ever explain the property of being alive. Today, although our understanding remains incomplete, this initial sense of mystery has largely dissolved. Biologists have simply gotten on with the business of explaining the various properties of living systems in terms of underlying mechanisms: metabolism, homeostasis, reproduction and so on. An important lesson here is that life is not ‘one thing’ – rather, it has many potentially separable aspects.”

Seth goes on to argue for a “real problem” strategy, in which we should aim to map descriptions of consciousness at the level of subjective experience to objective descriptions of brain mechanisms. While I agree that there is certainly a lot of room for progress on the “real problem” front, we should not lose sight of the fact that consciousness actually is one thing: subjective experience.

There are many functions associated with consciousness, but ultimately, what we set out to explain (the explanandum) are its phenomenal properties, not cognitive functions (Ellia et al., forthcoming). Consciousness is what it feels like to be, and we experience it directly. In this crucial way, consciousness differs from everything else, including life. “Experience exists” is the only datum directly and indubitably given to each of us and it cannot be explained away by reducing it to something else. Consciousness is a fundamental aspect of reality, and it comes before the physical.

Seth endorses phenomenal realism and yet insists on the utility of the analogy between consciousness and life. He gives two reasons in (Seth, 2021): first, that the analogy is useful in a historical sense, and second, that the subjective nature of consciousness does not preclude a successful science of consciousness.

In response to the first point, I would argue that appealing to historical precedent becomes unconvincing once we acknowledge that there is indeed something special about consciousness. It means we do not have a precedent for resolving the nature of something actually analogous to consciousness. With life there is no doubt that the explanandum itself is functional (and there never was much of a disagreement about this either, see (Chalmers, 1995)). Life does not have subjective quality (at least as long as it is not conflated with consciousness at the outset).

[You might say “but I know that I am alive”. But in which way do you know that? I would argue that it is through observation of other beings, forming a concept of “being alive” based on joint functional characteristics, and then applying this notion to yourself. This is not first-person, subjective knowledge. Descartes’ indubitability argument does not work for “life”.]

With respect to Seth’s second point, the fact that we can be objective about the subjective cannot be overstated. However, this insight surely does not rely on comparing consciousness to life. Instead, it is here that the disanalogy between life and consciousness becomes critical: Provocatively, one could say that “being alive” is just a label. It summarizes a set of functional properties, but it does not add anything above and beyond the observable processes that it comprises. This is why it could be “dissolved when biologists stopped treating life as one big scary mystery” (Seth, 2021). If we do the same with consciousness, we will have missed the target.

Life might be an illusion, consciousness is real

There are of course those who question the reality of phenomenal consciousness (e.g., Dennett, e.g. 2017; Frankish, 2016). In this view, all there is to explain are cognitive functions—that there is something it feels like is just an illusion. If consciousness is defined in purely functional terms, the analogy with life may seem appropriate. But even here there is a disanalogy, because for consciousness we would still need to explain where the illusion of feeling comes from.

There is a different sense, though, in which life rather than consciousness might be an illusion. For all we know to date, “life” might not be real: there might not be a well-defined set of natural processes that corresponds to being alive. Not all “living” creatures necessarily need to share a common set of properties (Sagan, 2010). In other words, “life” might be a fuzzy notion similar to “games” (see Abbott and Persson (2021)).

Arguably, this would not be much of a problem (Machery, 2012). Take the classic case of a virus. Depending on how we define life, a virus may or may not count as “alive.” Yet the virus itself couldn’t care less about this label and neither need the virologist who studies it.

[In general, it is also useful to distinguish the notion of “being alive” that applies to individual organisms from the processes of life in general (Lachmann and Walker, 2019). While the capacity to reproduce is widely recognized as a defining feature of life, for example, it cannot be a requirement for individuals to be alive. An answer to the question “What is life?” may not provide us with the tools to decide whether an individual system is alive and vice versa.]

That consciousness may also be an ill-defined class with fuzzy boundaries has been suggested by Patricia Churchland (1996), based on the observation that some contents of consciousness seem more elusive than others (e.g., self-awareness). However, this misses the point that there are clear cut experiences, and thus phenomenal consciousness is most definitely a thing. For a sophisticated robot it either feels like something to be or it does not and that makes all the difference.

On the other hand, we might of course still discover a universal principle underlying the notion of life. While life is clearly compatible with physics, in a recent article with the provocative title “The ‘hard problem’ of life” Walker and Davies (2016) suggest that we might need to move beyond our current description of the universe to properly account for life. Although I am sympathetic to the endeavor, the two “hard” problems are again not analogous in the relevant sense (at least from my side of the life-consciousness divide).

First, life may or may not correspond to a well-defined phenomenon in our universe. For consciousness, we have first-person evidence that it exists.

Second, let’s say we discover a set of information-based principles associated with macro-physical entities that match our intuitive notion of life so well that we’d be happy to say “this is what life is.” While these laws may be emergent, the explanation is still reductive. Life would then be “nothing more” than an emergent informational signature. Consciousness, however, would still be defined first and foremost by its phenomenal properties, even if we can account for them in physical terms.

A definition of life, a theory of consciousness

Reflective of the above is that the goal for “life”, in general, is to agree on a definition that matches paradigmatic cases and ideally is also useful, for example, for identifying life on other planets. For consciousness, the goal is a testable theory that allows us to study subjective experience in objective terms. To evaluate consciousness in difficult cases such as patients with brain lesions, animals that are very different from us, or also increasingly sophisticated robots, we must move beyond intuition. Whether someone or something is conscious or not is not a matter of definition.

Phenomenal consciousness is a thing with essential properties and structure, which can and should be characterized and explained. It is precisely in this way that we can hope to account for phenomenal experience through the methods of science (see Ellia et al., forthcoming). Any attempt to explain consciousness by dissolving it into multiple functional processes will ultimately be unsatisfactory.

I do believe that a successful scientific theory of consciousness that takes its subjective character seriously may ultimately explain the nature of consciousness in a satisfying manner (though this is not guaranteed). We should indeed not underestimate science, but we also need to discuss and likely update our scientific methods and understanding of what counts as a satisfactory explanation. In the case of consciousness, the explanation cannot be reductive. The life-consciousness analogy is a red herring.

[Acknowledgements: I want to thank Jeremiah Hendren for his helpful edits on an early draft of this commentary.]