Mary is a neurophysiologist. She knows very well what goes on in the neurophysiological structure of humans when they see color because she has studied all the physical information concerning the human perception when viewing colored objects, such as a yellow chair, blue book, and brown dog. However, she has never left her house, which is coincidently monochromatic, since the day she was born. The only color she has seen is the white color of her house. She knows about the outside world, yet in its colorless form, through a black-white television.
One day, because of a pressing matter, she has to leave the house. She could see the polychromatic world—in which there are green leaves, red roses, brown trees, and the blue sky—for the first time. “What a beautiful world”, she says. Despite the wonder, there is a problem here: providing that she comprehended all the physical information regarding the human perception of colors, would she learn a new lesson beyond all of her physical knowledge when seeing, for example, a red rose?
Frank Jackson says, “it seems just obvious that she will learn something about the world and our visual experience of it. But then it is inescapable that her previous knowledge was incomplete.”[i] Jackson’s answer is then well-known as the knowledge argument against physicalism: that Mary’s knowledge of the physical process is incomplete when perceiving color. When Mary sees a red color, for example, she will learn what it is like to see red color she has never found out before. That is the so-called qualia.
Jackson’s knowledge argument is one of the arguments against physicalism. Here are two other arguments that may also make us reconsider our acceptance of physicalism: 1) the explanatory argument, and 2) the conceivability argument. Those two arguments own the same tendency as the first one: that consciousness is irreducible to the physical explanation so as to be strong enough to put physicalism into question.
The explanatory argument is grounded in the distinction between the easy problem and the hard problem of consciousness. The easy problem of consciousness concerns the behavioral explanation and cognitive functions while the hard problem of consciousness concerns the question of why we can have conscious experiences.[ii] Physics, as is believed by Bertrand Russell and Arthur Eddington, merely tells us what matter does, not what it is. The task of physics, therefore, is providing mathematical models to accurately predict the behaviors of matter.
If the considerations of Russell and Eddington are true, physicalism can merely solve the easy problem of consciousness—insofar the reduction of consciousness to physical explanation has a sufficient epistemological precondition to be true. If the reductive explanation of consciousness turns out to be insufficient in the epistemological considerations, then physicalism fails to solve the easy problem of consciousness. Physicalism, therefore, in its utmost possibility for being true, has not yet been able to address the hard problem of consciousness. It has solely been able to explain how consciousness works.
On the other hand, the conceivability argument is related to a metaphysical possibility. According to this argument, we can coherently imagine that there are creatures, say, in a parallel universe that are physically identical to us. There is a part, however, differentiating them from us: that they have no consciousness. They are the so-called zombies. Even though zombies do not exist in our universe, we nevertheless can imagine them without encountering logical contradictions.
From the conceivability of zombies, this argument draws a metaphysical conclusion that zombies—even though they do not exist in our natural world—are metaphysically possible things. If the world of zombies which are physically identical to our world might exist without consciousness, the nature of consciousness is necessarily non-physical. In other words, the world of zombies is a creature that God has not yet finished. Having created all the physical components of the world of zombies, God forgot or got tired of further working to create a consciousness for such a world. The world of zombies, therefore, is physically identical to us, but minus consciousness.
We can set forth those three mentioned arguments in a syllogism as follows[iii]:
- The knowledge argument
- Mary knows all the physical facts;
- Mary does not know all the facts;
- Then, the physical facts do not exhaust all the facts.
Here is the one formulated more generally:
- If there are truths about consciousness that are not deducible from physical truths, then physicalism is false;
- There are truths about consciousness that are not deducible from physical truths;
- Then, physicalism is false.
- The explanatory argument
- Physical accounts explain structure and function at most;
- Explaining structure and function does not suffice to explain consciousness;
- Then, no physical account can explain consciousness.
- The conceivability argument
- If it is conceivable that there are zombies, then it is metaphysically possible that there are zombies;
- If it is metaphysically possible that there are zombies, then consciousness is non-physical;
- It is conceivable that there are zombies.
- Then, consciousness is non-physical.
Here is the one formulated more generally with P denotes physical truths and Q denotes phenomenal truths:
- If it is conceivable that P&~Q, it is metaphysically possible that P&~Q;
- If it is metaphysically possible that P&~Q, then physicalism is false;
- It is conceivable that P&~Q;
- Then, physicalism is false.
As I mentioned above, those three arguments have a common tendency, namely asserting the impossibility of a reductive explanation of consciousness because of an epistemic gap between consciousness and the physical universe. From the fact that there is an epistemic gap between consciousness and physical universe, they draw another conclusion that there is also a metaphysical gap between them and hence physicalism explaining consciousness by using physical explanations is not defensible.
The deadlock faced by physicalism has brought about a new topical discourse in the philosophy of mind. Recently, a view named panpsychism has appeared. The proponents of panpsychism, such as David Chalmers, Galen Strawson, and Philip Goff, believe it can disentangle the deadlocks physicalism is not able to tackle. This view posits everything (pan) has consciousness or a consciousness-involving nature (psyche).[iv] Panpsychism, therefore, can solve the easy problem of consciousness at least: we can have conscious experiences out of everything, including physical objects like atoms, has a certain degree of consciousness. The human consciousness, according to panpsychism, is a complex and sophisticated consciousness. It springs from a combination of billions of subatomic consciousness.
At that point, although it seems capable of solving the hard problem of consciousness, I am not in favor of panpsychism because of two reasons. The first reason which has been the common criticism of panpsychism is the so-called combination problem: how can some consciousness in their respective degrees at the micro-level combine to form a human consciousness? The second one is the ontological claim of panpsychism including everything that exists—in the sense it expands its ontological claim from humans to non-humans; or more specifically from the mind to outside the mind. By claiming that everything has a consciousness, panpsychism falls into a kind of ontological monism asserting that consciousness is the only fundamental aspect of the world as it is omnipresent and covering anything. That is to say, this world has basically a single and universal trait, namely consciousness. In that context, panpsychism is actually in a parallel position with physicalism, only in the otherwise form.
In a caricatural criticism, we can say: if a chair on which I was sitting has conscious experiences, it would moan in pain when, for example, a fat man replaced me sitting on it so that one of its legs were detached. Panpsychist anticipated such criticism by making a hierarchy of consciousness: that the consciousness of non-humans is positioned at the lower level. Therefore, in satire languages, it can be said that panpsychism believes: when a human being is hurt she will write a poem, then when a stone is crushed by a truck it can show a sad emoticon.
In my view, therefore, panpsychism, to some extent, hides a theological tendency: as if there is an ultimate, universal trait covering everything exists. Accordingly, the solution it has offered to solve the hard problem of consciousness is an ad hoc and tautological solution. Why there is a conscious experience in the physical universe, the answer offered by panpsychism is everything has consciousness. This is the reason, regardless of asserting the unreliability of physicalism, I cannot accept panpsychism.
Having been dissatisfied with panpsychism, instead of returning to the camp of physicalism, I decided to look around phenomenology. By that look, I have discovered the Integrated Information Theory of Consciousness (IIT) whose theoretical construction was much inspired by phenomenology. Giulio Tononi, the founder of IIT, says that it is a translation of the seemingly ineffable qualitative properties of phenomenology into the language of mathematics.[v] Based on the phenomenology itself, I could accept IIT, yet not all its theoretical suppositions, but only some parts of them.
The theoretical construction of IIT has three core tenets, namely phenomenological axioms, ontological postulates, and identities.[vi] Instead of explaining consciousness by using physical accounts or the third-person perspective, IIT commences its explanation from phenomenological axioms or witnesses of the first-person. The phenomenological axioms, acknowledged by Giulio Tononi himself, are Cartesian (and I would like to call it Husserlian): that consciousness is unequivocal and self-evident so that it needs no external evidence for its existence. It is axiomatic in the sense we directly experience it from the first-person perspective.
The axioms consist of five points. 1) The existence of consciousness is a self-evident reality. 2) Consciousness is compositional—each conscious experience is structured, consisting of multiple aspects such as shape, color, sound, etc. 3) Consciousness is informative and specific. It means that each conscious experience contains an intrinsic criterion that distinguishes it from other possible conscious experiences. 4) Consciousness is integrated. It means that each experience is irreducible to its non-interdependent components. 5) Consciousness is exclusive because it always has definite borders.[vii]
Those five axioms are phenomenological data about consciousness that are directly experienced by us through the first-person perspective, not the third-person perspective. Axiomatic evidence in the realm of consciousness requires[viii] the ontological postulates on the physical system.[ix] For instance, the first axiom (that consciousness has an intrinsic existence) requires the first postulate on the physical system (that there is an intrinsically existing physical mechanism), as well as the other axioms.
It is obvious that the inference of ontological postulates is inferred from the phenomenological axioms, though the postulates are in fact ontological preconditions for the level of conscious experience. Indeed, the phenomenological axioms are early given as a self-evident to us, but the existence of those five axioms is ontologically made possible by those five postulates in the physical system. In other words, if there is a certain phenomenal quality, then there must be a physical system supporting it because there can be no former without the later. IIT, accordingly, claims that there is an identity between conscious experience and physical system so as to assume that we can mathematically measure the level of consciousness based on the level of integrated information (Φ) in the physical mechanism.
According to IIT, therefore, the phenomenological axioms are only primordial epistemologically, but not ontologically. The phenomenological axioms are merely given convincingly to us earlier, but it is the physical system that determines the level of conscious experience subsequently. IIT, hence, has two possibilities I have denied since the beginning. Firstly, it is obvious that IIT can plummet into the same place as panpsychism: that the outside-human objects have possibly a conscious experience as long as they have the ontological postulates that can generate the phenomenological axioms. Secondly, although IIT does not reduce the explanation of consciousness to physical explanation, ontologically, it nevertheless supposes a physical precondition to generate conscious experience.
To avoid those two possibilities, I am only going to accept the phenomenological axioms of IIT and deny two other tenets. I take the phenomenological axioms of IIT as a theoretical formulation of Edmund Husserl’s phenomenology of consciousness. This following quotation originated from Husserl’s manuscript of 1910 can explain how Husserl projected phenomenology as metaphysics of consciousness:
Consciousness—and this is the fundamental error constituting the ultimate error of psychologism (an error to which not only all empiricists succumb but all rationalists as well)—is not a psychical experience, not a network of psychical experiences, not a thing, not an appendage (state, action) to a natural object. Who will save us from the reification of consciousness? He would be the savior of philosophy, indeed, the creator of philosophy.[x]
Phenomenology as metaphysics of consciousness, as it is implicit in the given quotation, is firstly a project to end the reification of consciousness. Husserl, therefore, takes phenomenology as an eidetic or a priori science of pure consciousness and its correlates. In that sense, he distinguishes phenomenology and metaphysics. The latter, according to him, concern actual realities or actualities, whereas the former, on the other hand, is related to ideal possibilities. He said, thus, that the first philosophy is not metaphysics, but phenomenology, since the possibility of the world precedes its actuality. Phenomenology, therefore, is metaphysics in the most fundamental sense.
[i] Frank Jackson, “Epiphenomenal Qualia”, in The Philosophical Quarterly 32, no. 127 (1982), 127-136
[iii] I took that formulation with little changes from David J. Chalmers, Ibid., 106-109
[iv] David Skrbina, Panpsychism in the West (Cambridge: The MIT Press, 2005), 2.
[v] Giulio Tononi, “Integrated Information Theory of Consciousness: An Updated Account”, Archives Italiennes de Biologie, 150 (2012), 290-326.
[vii] Ibid., Bdk. Masafumi Oizumi, Larissa Albantakis, dan Giulio Tononi, “From the Phenomenology to the Mechanisms of Consciousness: Integrated Information Theory 3.0”, PLoS Comput Biol 10(5): e1003588. DOI:10.1371/journal.pcbi.1003588
[ix] Although the term ‘axiom’ and ‘postulate’ is often interchangeably used, Masafumi Oizumi, Larissa Albantakis, and Giulio Tononi in “From the Phenomenology to the Mechanisms of Consciousness: Integrated Information Theory 3.0” use it in the traditional understanding that differentiates the meaning of the two terms: axiom is a self-evident truth, whereas postulate is an unproven assumption that can serve as the basis for logic or heuristics.
[x] As cited by Rudolf Bernet, Iso Kern, Eduard Marbach, Introduction to Husserlian Phenomenology (Evanston: Northwestern Press, 1993), 62.