Science and experience constrain and modify each other as in a dance.Francisco Varela (1996, p. 347)
Plenty of puzzles about consciousness remain—unknowns on which further empirical work will plausibly shed light. What kinds of actual or hypothetical entities are conscious, and how similar are their experiences to our own? Ethologists and the average pet owner have concluded from behavioral observations that animals like dogs and cats, with relatively sophisticated nervous systems, very likely have experiences. But what about simpler animals, like insects? What about plants, bacteria, or complex machines like computers or smart phones? Might other “inanimate” objects have a modicum of anima, a hushed buzz of inner life? What kinds of physical activity correspond to consciousness in general, or to specific features of experience like painfulness, bitterness, or blueness? Neuroscience has progressed enough to begin answering these last two questions with regard to human physiology. But many philosophers and scientists have suspected that the physical correlates of consciousness are not limited to the activity of organic materials. Rather, according to the position known as “functionalism,” consciousness can be realized in a variety of physical media, including inorganic materials like silicon, as long as certain functions are carried out, as long as enough of the structure is preserved. The big question is: how much structure is enough?
There are some serious obstacles to answering these questions, since we can never directly experience what another cognitive system experiences. But while we will never attain a foolproof confirmation of experiences beyond our own (when is science ever foolproof, anyway?), further scientific research can help us narrow down our hypotheses, and become more confident in particular theories.
What about the “hard problem of consciousness”—the question of why there is this strong link between conscious events and certain kinds of physical events? In Part 1 and Part 2 of this series, I proposed that the existence of this relation is not a mystery, but a marvel: a fact that is surprising, counterintuitive, or awe-inspiring, but not in need of further explanation. I argued that the best way to classify the relation is either as an identity or as an inseparable unity of distinct, but complementary properties or “modes” (i.e., a double-aspect theory, like Spinoza’s). I confess that I have oscillated between these views over the years, and between regarding the distinction as important and unimportant. In this third and final post of the series, I will explore possible reasons to favor one of these positions over the others, and sketch out where I think our academic energies should be rerouted if the hard problem is dissolved.
Can scientific experimentation adjudicate between the two views? Does one theory make different predictions than the other? It appears not. Both theories would lead one to expect consciousness where there is physical activity of a particular kind, and vice versa. Let’s suppose that we observe an event with no known physical explanation. Could we argue that this is evidence for the causal influence of an irreducible, nonphysical property of consciousness, and therefore evidence in favor of the double-aspect theory? That would be extremely hasty, methinks. Regardless of our psychophysical theory, experience leads us to expect that observed events of any kind (whether accompanied by consciousness or not) will be in accord with the laws of physics and continuous with the chain of physical causes. Our first impulse when confronting an event with no known physical explanation should be to search for ways it might connect to what we know from physics.
Can introspection settle the dispute? Suppose we are examining our own experience of scarlet wildflowers against the cerulean background of the ocean (see Figure 6 below). Some may contend that in the redness of the wildflowers or the blueness of the ocean, they discern something that goes beyond a functional event (like information-processing), something that is certainly not identical to the activity of a neural network. This extra ingredient they take to be a nonphysical, irreducible property of experience—a “quale” in modern Philosophese (plural: “qualia”)—and therefore evidence in favor of a double-aspect theory over an identity theory.
It is true that we do not see the firing of neurons in this experience, but that’s because we lack perceptual access to that information. We readily accept ignorance or blindness of this sort with respect to objective phenomena; why not with respect to subjective phenomena, as well? Furthermore, I’m not so sure I can disentangle functional properties from the character of my experience. There is a wealth of information here that I am accessing and processing, various features that I am discriminating, locating, identifying, and evaluating. These processes are “baked into” the very experience of seeing red or blue. In other words, it isn’t clear to me on the basis of introspection that a distinction between physico-functional and experiential properties is appropriate.
Does one of these theories contribute better to our understanding of consciousness and truth-preserving discourse about it? We might fear that adopting an identity theory would licence eliminating the experiential side of the equation, leaving behind a discourse and a taxonomy in purely physical or functional terms. Since we are ignorant of many ways in which physical and conscious events are linked, this ontological purge would result in an incredible loss of information about our most precious treasure, consciousness. For anyone who did not possess the secret, unspoken knowledge of that link, the resulting picture of reality would depict a universe of experiential desolation, inhabited solely by philosophical zombies (see Figure 7 below). It would hinder us from addressing a multitude of ethical questions regarding the consciousness—including the pain and pleasure—of humans, other animals, and machines.
I agree that it would be detrimental, to both our ethics and our understanding of consciousness, to eliminate the terms we have developed in everyday speech to name the manifest side of our experience and its features. The “manifest image” (Wilfrid Sellars, 1962) is not to be rejected, but refined by the scientific one. Since we lack knowledge and intuitions concerning the connections between physical and conscious events, we must preserve both sides of the equation, enabling us to speak of the bridges between them. If the relation is described as an identity, it should be non-eliminative with regard to experiential terminology in our discourse and scientific methodology.
More important than deciding between subtle differences in classification (say, between a non-eliminative identity theory and a double-aspect theory) is developing a methodology that will help us discover and communicate the precise connections between physical and conscious events. The biologist, philosopher, and neuroscientist Francisco Varela (1998) outlines such a methodology, which he calls “neurophenomenology.” Phenomenology is a disciplined approach to examining our experience, a careful and systematic form of introspection. It was launched in Western thought by Edmund Husserl and developed by William James, Eugen Fink, Edith Stein, Roman Ingarten, and Maurice Merleau-Ponty, among others (Varela, p. 335). There has been a rich development of phenomenology in Eastern thought, as well—for instance, in Buddhist practices of meditation and mindfulness, and in the Kyoto School of Nishida Kitaro and Nishitani Keiji (ibid.). The “neuro-” in “neurophenomenology” is meant to encompass various sciences that are pertinent to the study of consciousness, including evolutionary biology, psychology, and neuroscience (330).
Varela makes a number of claims in his paper, some of which I would dispute, but his principal point is this:
Phenomenological accounts of the structure of experience and their counterparts in cognitive science relate to each other through reciprocal constraints. The key point here is that by emphasizing a co-determination of both accounts one can explore the bridges, challenges, insights, and contradictions between them. This means that both domains of phenomena have equal status in demanding a full attention and respect for their specificity. It is quite easy to see how scientific accounts illuminate mental experience, but the reciprocal direction, from experience towards science, is what is typically ignored.Francisco Varela (1996, p. 343)
In other words, a science of consciousness should wed disciplined, first-person examinations of experience (phenomenology) with scientific theories and observations of behavior and physiology. Discoveries in one domain provide insights for the other. For example, suppose that a person examining the scene in Figure 6 above undergoes neuroimaging. Suppose that the neuroimaging reveals patterns of activity associated with a fear response, but the subject initially does not report any fear. The fear might reside at an unconscious or semi-conscious level, but it might also be a conscious feature overlooked later by the reporting subject. Being informed of this observation, the subject responds, “You know, I guess I did feel a little anxious looking at this photo. I’m terrified of heights, and it looks like those flowers are right on the edge of a cliff!”
Of course, experimenters must be wary of influencing a phenomenological report by what they tell their subjects. In the case above, it is unclear whether a conscious fear was overlooked, or an unconscious fear was elevated to consciousness by being addressed by the experimenter. This is one example of how complex and challenging the study of consciousness can be. But it is also meant to illustrate the way that phenomenology and scientific observation can constrain and modify each other, “as in a dance.” Observations of behavior or neural activity can draw attention to what may have been experienced, but unreported; careful phenomenological reports are required for corroboration about what, in fact, was conscious.
Since Varela published his paper on neurophenomenology in 1996, a number of leading scientists in consciousness research have embraced several aspects of the approach. The cognitive psychologist Stanislas Dehaene (2014), for example, has identified the task of “taking subjective reports seriously” as a “key ingredient to the new science of consciousness” (11). He writes:
It was not enough to present people with two types of visual stimuli; as experimenters, we had to carefully record what they thought of them. The participant’s introspection was crucial: it defined the very phenomenon that we aimed to study. If the experimenter could see an image but the subject denied seeing it, then it was the latter response that counted—the image had to be scored as invisible. Thus, psychologists were forced to find new ways of monitoring subjective introspection, as accurately as possible.Stanislas Dehaene (2014, p. 11)
Dehaene does not go into much detail about how best to gather subjective reports or interpret their “raw data” (12). The burden of accuracy, I think, should fall not only on the experimenters, but on the subjects, as well. Varela highlights this point:
[A]s more sophisticated methods of brain imaging are becoming available, we shall need subjects whose competence in making phenomenological discriminations and descriptions is accrued.Francisco Varela (1996, p. 341)
I agree with Varela that building this competence is a blind spot in Western education. We face challenging questions about how to establish guidelines for the examination and documentation of something so apparently private and ineffable as experience. I plan to explore these questions further in a future post.
In conclusion, I have argued for a shift in philosophical focus: from weighing subtleties in the metaphysics of mind, to developing methods and testable theories in the interdisciplinary search for the physical signatures of consciousness. But if I had to choose a metaphysical theory, where would I stand? Currently, I lean toward a non-eliminative identity as the best way to conceptualize and talk about the link between physical and conscious events. The physical, in my usage here, encompasses the functional, or types of activity at a higher level of abstraction than chemical types. I’ll discuss the merits of functionalism in my next series of posts.
A non-eliminative identity is also the way that most scientists of consciousness today talk about the mind-body relation. They retain experiential terms in their discourse, such as “pain,” “pleasure,” “experience of blue,” or “consciousness” in general, but treat the phenomena so-named as physical ones, of which a variety of other physical or scientific properties are predicated. They say things like:
- Conscious events occurred in such-and-such place, at such-and-such time; “Consciousness lives in the loops: reverberating neuronal activity, circulating in the web of our cortical connections[…]” (Dehaene, 2014, p. 156).
- “[C]onsciousness has a precise role to play in the computational economy of the brain—it selects, amplifies, and propagates relevant thoughts” (p. 14).
- “[C]onsciousness is often too slow to keep up with a fast rate of image presentation on screen” (p. 33).
- “Consciousness is an evolved function […]—a biological property that emerged from evolution because it was useful” (p. 88).
- Consciousness is “efficacious” (William James, qtd in Dehaene, p. 89).
- “Consciousness is brain-wide information sharing” (p. 161).
Spatiality, temporality, functionality, speed, evolvability, and causal efficacy are all physical or objective properties appropriately attributed to consciousness, to subjective experience. Asserting such things does not amount to a Rylian category mistake, nor a conflation between consciousness and its putatively distinct, physical “backside,” as double-aspect theory would have it. Insisting on that distinction would not be warranted by experience itself, I believe—and furthermore would prompt some rather cumbersome circumlocutions in discourse about consciousness.
Perhaps with the advent of autumn, the ardent reds and yellows that dapple my field of experience will convince me that some aspect of their nature is nonphysical and irreducibly subjective, and I’ll sway toward the double-aspect theory again. Or I’ll re-read Erwin Schrödinger’s Mind and Matter (particularly Chapter 6, “The Mystery of the Sensual Qualities”) and in that manner find myself seduced anew by Spinoza’s bimodal picture of substance. I’m open to be corrected by the Cosmos, by the revelations of nature and the insights of my conscious kith and kin. Leave a comment below if you think I’ve taken a wrong turn.
For now, I’m happy to lull the hard problem to sleep, to let it dissolve like a lemon-flavored lozenge, and turn my attention to a matter of greater moral urgency: the problem of other minds. This problem is wrapped up with the quest for the neural correlates—or better, “signatures” (Dehaene, p. 142)—of consciousness. It is also related to what the philosopher Ned Block (2002) calls the “harder problem of consciousness” (oh boy!). A neurophenomenological approach is the way forward, I think, but what can we conclude so far? Australian octopuses, conscious quarks, and Amazon’s Alexa, among other curious entities, will make appearances in this next series. I hope to see you there!
Block, Ned (2002). The harder problem of consciousness. Journal of Philosophy 99 (8):391-425. Retrieved online at: http://www.nyu.edu/gsas/dept/philo/faculty/block/papers/HarderProblem.pdf.
Dehaene, Stanislas (2014). Consciousness and the brain: deciphering how the brain codes our thoughts. New York: Penguin Books.
Schrödinger, Erwin (1958). Mind and Matter. In What Is Life? The Physical Aspect of the Living Cell with Mind and Matter & Autobiographical Sketches. Cambridge: Cambridge University Press, pp. 91-164. Retrieved online at: http://strangebeautiful.com/other-texts/schrodinger-what-is-life-mind-matter-auto-sketches.pdf
Sellars, Wilfrid (1962). Philosophy and the scientific image of man. In Frontiers of Science and Philosophy, Robert Colodny (ed.). Pittsburgh, PA: University of Pittsburgh Press: 35–78. Retrieved online at: http://selfpace.uconn.edu/class/percep/SellarsPhilSciImage.pdf.
Varela, Francisco (1996). Neurophenomenology: a methodological remedy for the hard problem. Journal of Consciousness Studies, 3, No. 4, pp. 330-49. Retrieved online at: https://unstable.nl/andreas/ai/langcog/part3/varela_npmrhp.pdf.
Follow this Blog
Get new content delivered directly to your inbox.