Phi is easily the most unusual book on consciousness I have read in awhile. It’s hard to describe, but Tononi makes his case for “integrated information” using poetry, art, metaphor, and fiction. Each chapter is a fictional vignette or dialogue between characters inspired by famous scientists like Galileo, Darwin, or Francis Crick. At the end of every chapter is a “note” written in normal academic language explaining the context of the stories. On just about every page there are huge full-color glossy pictures of famous art. The book is simply beautiful as a physical object in an attempt, I suspect, to convince qualiaphiles that Tononi is “one of them”.
The theory of integrated information itself, however, is less appealing. Here is how integrated information is defined:
Integrated information measures how much can be distinguished by the whole above and beyond its parts, and is its symbol. A complex is where reaches its maximum, and therein lives one consciousness- a single entity of experience.
And with that Tononi hopes the “hard” problem of consciousness is solved. However, the intellectual weight of Phi rests on a thought experiment involving a photodiode. A photodiode discriminates between light and no light. But does the photodiode see the light? Does it experience the light? Most people would think no. But the photodiode does integrate information (1 bit to be precise) and therefore, according to the theory of integrated information, has some experience, however dim. The theory of integrated information is therefore a modern form of panpsychism based on the informational axiom of “it from bit”. For obvious reasons Tononi downplays the panpsychist implications of his theory, but he does admit it. Consider this quote:
“Compared to [a camera], even a photodiode is richer, it owns a wisp of consciousness, the dimmest of experiences, one bit, because each of its states is one of two, not one of trillions” (p. 162)
The reason the camera is not rich is because it can be broken down into a million individual photodiodes. According to Tononi, the reason why the camera has a low level of compared to a brain is that the brain integrates information between all its specialized processors and the camera does not. But nevertheless, each photodiode has a “wisp of consciousness”.
Tononi also uses a thought experiment involving a “qualiascope”, a hypothetical device that measures integrated information and can therefore be used to detect consciousness in the world around us. In the vignettes, Tononi writes that when you use the qualiascope:
“‘You’ll look in vain at rocks and rivers, clouds and mountains,’ said the old woman. ‘The highest peak is small when you compare it to the tiny moth'” (p. 222).
This is how he downplays his panpsychism. Notice how he doesn’t say that rocks and clouds altogether lack consciousness. It’s just that their “highest peak” of is low compared to a moth. The important part however is that the of rocks and clouds is low but not nonexistent.
Why is this important? Because Tononi wants to have his cake and eat it too. To see why just look at some of his chapter subtitles:
Chapter 3 “In which is shown that the corticothalamic system generates consciousness”
Chapter 4 “In which is shown that the cerebellum, while having more neurons than the cerebrum, does not generate consciousness.”
This is because Tononi admires the Neural Correlates of Consciousness methodology founded by none other than Francis Crick, who has a strong intellectual presence throughout the book. According to most NCC approaches, consciousness seems to depend on “corticothamalic” loops and not just specialized processors alone (like the cerebellum).This finding comes from research correlating behavioral reports of consciousness with activity of the brain. When most people report being conscious, higher-order system loops are activated. And in monkey experiments the “report” is a judgement about whether they see a stimulus, which can be made by pressing a lever. What they find in the NCC approach is that consciousness seems to depend on more than just specialized processors operating alone. It requires a kind of globalized network of communicating modules to “generate” consciousness.
It should now be plain as day why Tononi is inconsistent in trying to have his cake and eat it too. If a lowly inorganic photodiode has a “wisp of consciousness”, then clearly, by any standard, a single neuron also has a wisp of consciousness, as well as the entire cerebellum. Tononi acknowledges this:
“Perhaps a whiff of consciousness still breathes inside your sleeping brain but is so feeble that with discretion it makes itself unnoticed. Perhaps inside your brain asleep the repertoire is so reduced that it’s no richer than in a waking ant, or not by much. Your sleeping would be much less than when your brain is fast awake, but still not nil” (p. 275).
“Early on, an embryo’s consciousness – the value of its – may be less than a fly’s. The shapes of its qualia will be less formed than its unformed body, and less human than that: featureless, undistinguished, undifferentiated lumps that do not bear the shape of sight and sound and smell” (p. 281)
” may be low for individual neurons” (p. 344)
But if a single neuron has a wisp of consciousness, then clearly consciousness is not “generated” by the corticothalamic system. It is instead a fundamental property of matter itself. It from bit. What Tononi means to say with his chapter subtitles is that “The corticothalamic system generates the right amount of to make consciousness interesting and precious to humans”. The difference between the photodiode and the corticothalamic system is a difference of degree. The corticothalamic system has a high enough level such that it makes an interesting difference to human experience such that we can report or notice it, distinguishing coma patients (very low ) from awake alert adults (very high ).
But now there is an interesting tension in Tononi’s theory. If there is a low but nonnegligible amount of in a human embryo, Tononi’s theory must now figure out how to make a cut-off point between the lowest amount of we actually care about so we can figure out when to stop giving people abortions. Until Tononi answers that question, his “solution” to the hard problem of consciousness is fairly disappointing. He came up with this notion of integrated information to explain qualia, but now we are faced with the difficult question of “How much is necessary for us to care about?” Clearly no one really cares about the “wisp of consciousness” in a photodiode. So having solved the “hard” problem of qualia, Tononi just creates an equally difficult problem: how to figure out the amount of worth caring about from a moral perspective. And he plainly admits he hasn’t solved these problems.
But for me this is a huge problem. You can’t have your cake and eat it to if you are a panpsychist. You can’t say that photodiodes are conscious but then say the only interesting consciousness is that of corticothalamic systems. This seems rather ad hoc to me; a solution meant to fit into prexisting research trends. If you are a panpsychist you should embrace the radical conclusion. According to theory, Consciousness is everywhere. It is not “generated” in the brain. It only reaches a high level of in the brain. And if that’s the case, then the entire methodology of NCC is mistaken. NCC is not a true NCC but rather the “Neural Correlates of the Amount of Consciousness Humans Actually Care About”.
Overall conclusion: Phi is an interesting book and worth borrowing from the library. But I wouldn’t say it adequately solves the hard problem of consciousness. Not even close. What it does is arbitrarily stipulate criteria for pointing out consciousness in nonhuman entities. But Tononi never makes a real argument beyond appeals to intuition for why we should accept a definition of consciousness such that the ascriptions come out with photodiodes having a “wisp” of consciousness. I think most people will want to define stipulation criteria such that the ascriptions come out with only biological creatures having consciousness. Panpsychism is just too radical for most. So while I applaud Tononi for exploring this ancient idea from a modern perspective, I ultimately think that when people truly understand that Tononi is a panpsychist they will be less attracted to it despite its close relationship to Francis Crick and the wildly popular NCC approach.