The Part Problem

People talk about the mind-brain problem, but that is strictly inaccurate. The problem isn’t about how the brain as a whole produces consciousness; it’s about how some of it does. It isn’t about how the brain differs from other bodily organs; it’s about how certain parts of it do. The various parts of the brain look very similar and function similarly, but only a subset of brain parts have the magic touch. What makes them so special? What ingredient do they possess that other parts don’t possess? This is what I am calling the part problem. It refocuses the so-called mind-body problem: how do you convert a bit of the brain that doesn’t produce consciousness into a bit that does? It can hardly be a change of location, as if transplanting neurons from the brain stem into the frontal cortex will magically transform them into agents of consciousness (or if it does, we would want to know how). Nor are the consciousness neurons bigger or brighter than the non-conscious neurons. Nor do they fire more rapidly. There seems to be no chemical or anatomical difference. And it can hardly be supposed that God arbitrarily chose these neurons to be consciousness-bearing ones (“I anoint thee guardians of the soul”). The part problem looks like a hard problem—as hard as the mind-body problem, or even harder. For it introduces an element of arbitrariness into the picture: all neurons seem the same yet only some have the power to produce consciousness. Then, in virtue of what do they have this power? Is there just no answer to this—is it just a freak of nature, or evidence of a hidden world? But why this portal instead of that one? It’s like supposing that a given chemical can explode or not explode without changing. Is it the environment of the neuron that makes the difference? But why? The puzzle is almost violently difficult. We might call it the infuriating problem.

Take a part of the brain that has no consciousness associated with it. Now consider a neighboring part that does have a conscious correlate. How does one part grade into the other? Is there some intermediate state of semi-consciousness? Can there be consciousness migration or consciousness spread? Could they change places consciousness-wise? Is the difference exceedingly subtle or quite manifest? Could a tiny variation of shape make all the difference? Neurophysiologists have looked at both types of cells under the microscope and detected no physical difference, and yet the difference could not be more marked. What proportion of brain cells are mentally employed? I have never heard an estimate. Is it mainly unconscious? Is this ratio the same for all animals with a brain? If so, why? When the brain dies consciousness disappears from its precincts, the light goes out, but what physiological difference between the two types of cells accompanies this, if any? If you were trying to build a conscious machine, would you install two types of components, corresponding to the two types of neurons? Is one a necessary condition of the other? When brains evolved did the unconscious neurons appear first and the conscious ones build on this foundation, or were there always the two types? How are the two developmentally scheduled in embryogenesis? Is one more active than the other? There is surely some physical difference, but we are damned if we can see what it is. The whole set-up seems contrary to reason, and yet these are the facts. This division of labor within the brain is a complete mystery. Why are some neurons not conscious? They ought to be if others are. This conundrum appears to favor some sort of substance dualism: are we then to take that possibility more seriously than we have? Materialism seems defeated in the face of it. But then we will be confronted by the problem of how and why the mental substance selects certain neurons as its locus of influence and not others. We thought that neurons contained some special mental ingredient that sets them apart from other cells in the body, but it turns out they don’t, since some neurons have nothing to do with consciousness. So, are neurons really beside the point? Some are correlated with consciousness, but this may not be because they produce consciousness, since some don’t. But then, we are completely in the dark about the basis of consciousness. Maybe we are looking in the wrong place altogether. The part problem makes the mind-brain problem even harder, even more maddening.

Here is a comparison to make the point vivid. Suppose you are investigating water and are interested in explaining its liquid state. You arrive at the theory that liquidity is the loose arrangement of the constituent H2O molecules. Well and good, you think, we have that problem under control. But then you discover, to your surprise, that not all H2O molecules loosely bonded are liquid! How can that be? The molecules are exactly the same as in the liquid water but the water is not liquid! Obviously, your theory of liquidity is wrong, but you can discern no difference between the two cases: here liquidity, there no liquidity—but exactly the same chemical make-up. It seems impossible, but it is an observable fact. Nature has gone mad, or you have (are you hallucinating?). In the one case, the micro properties produce liquidity; in the other, they do not. How can this be? Is there some other source of liquidity that you are somehow missing—a sort of immaterial liquidity?

Animal Induction

Hume argued that induction is based on custom not reason. We believe in induction because we are psychologically built that way by nature not by ratiocination. He could have cited the case of animals: they act according to induction by instinct; they were not taught to do so or employ a priori reflection. We could say they have an inductive gene; it’s an adaptation brought about by natural selection. Induction is like a thick coat in the Arctic. The environment calls it forth. We evolved from animals, so our inductive dispositions have the same roots. This is why the skeptical argument makes so little impact on us. We are natural-born inductivists. Popper can’t budge us on this. Even if the uniformity of nature breaks down, we are genetically inclined to induction. In this sense we have an innate inductive philosophy. People talk about commonsense philosophy; we also have an instinctive philosophy installed by the genes under natural selection. Our instinctive philosophy is inherited from our animal ancestors going back a long way. We are not a blank philosophical state. Induction is an “innate idea”. It is like our philosophy of substances—a natural innate cognitive-behavioral scheme. We go by laws instinctively. We have an inductive brain(-stem). Our DNA is inductive.

This doesn’t prove that induction is a valid mode of inference. We cannot use it to prove that the future will be like the past; we might even stop behaving inductively! Just because we have always been inductive in the past doesn’t prove we will continue to be inductive in the future. Nature might also stop being uniform while leaving us still committed to induction. You never know. But we can infer that nature was uniform in the past, i.e., that our ancestors evolved in conditions of uniformity. For there would have been no induction in a world lacking in uniformity, because it would not have been adaptive. Adaptations evolve to suit the world surrounding the organisms in question, so we know our ancestors lived in a predictable uniform world. The inductive gene only gets installed if it is adaptive in the given environment. Hume would have enjoyed the post-Darwinian world of genes and evolution from earlier species.

Allegations and Obituaries

Anybody can make any allegation against anyone. It means nothing. Allegations are not evidence. This is obvious, though often forgotten. The OUP gives us: “a claim that someone has done something wrong, typically an unfounded one”. An allegation is a claim not a report, an assertion not a fact. It is as easy to make an unfounded allegation as a founded one. The gap between saying and being is enormous and principled. It is not like the gap between sensory impressions and facts: an impression is evidence (though not conclusive evidence) of fact. An allegation is a voluntary act of speech causally untethered to reality, but a sense impression is an involuntary state on mind typically caused by what it purports to represent. It gives an appearance of reality, while an allegation does no such thing: when you hear an allegation it doesn’t seem to you that the world is as alleged. We should not confuse these two types of relation. An allegation is not a perceptual impression of what is alleged. It is not a sense-datum. A false allegation is nothing like a visual illusion. This is why allegations always stand in need of supporting evidence; you can never be convicted on allegation alone. Allegations are just words, and words are not necessarily connected to facts, nomologically or otherwise. Allegations never by themselves imply truth, even weakly. Just because somebody says it doesn’t mean it’s true. When we acquire knowledge by testimony, our evidential basis is not the fact of assertion alone but the evidence we have of the reporter’s veracity, which must be independent of the assertion currently being made, to the effect that the speaker is reliable. This never consists in further assertions by that speaker; the circle of assertion must be broken out of. No allegation can be supported by other allegations alone; nonlinguistic facts must be adduced. Allegations in themselves are epistemically null. Their existence does not raise the probability of what is alleged. Indeed, they may lower the probability if the speaker is a known liar or unreliable idiot or certifiably insane. Allegation is never demonstration, or even indication. The law is very clear on this and insists upon it, rightly so.

I say all this because newspapers (etc.) have taken to mentioning in obituaries that the deceased person has been alleged to have done such-and-such. This is a very bad practice. By all means mention actual findings against the person, if such there be, but don’t mention mere allegations. If the practice were consistently applied, obituaries would be stacked with the lies of the person’s enemies; lies would be manufactured for precisely this purpose. The only reason to mention allegations, often salacious, is to indicate or suggest that the allegations are credible; but no proof of credibility is given, and the facts often contradict the allegations. Unproven allegations should not be cited, because doing so conversationally implies that there is reason to believe them, but there may be no such reason. Innocent people have allegations made against them all the time from a variety of motives, so don’t buy into these allegations by mentioning them. And don’t reply that it is a fact that such allegations were made and you are just reporting facts: if I allege falsely and maliciously that you are a child murderer, should that fact (that I made this allegation) find its way into your obituary? Of course not. Mentioning allegations only gives readers the impression that there must be substance to the allegations, or else you wouldn’t mention them. Report findings of guilt not imputations of guilt: truth not opinion (or mere assertion). Surely, this is obvious.[1]

[1] The case of John Searle is a case in point.