Easy and Hard Problems

Easy and Hard Problems

It has become customary to speak of “the hard problem of consciousness” and “easy problems [of consciousness]”. I think this is an unhelpful way to talk; it is too simple-minded. In the first place, we should not say that consciousness itself is a hard problem; rather, its relation to the brain is a hard problem. That is, the brain-consciousness problem is a hard problem. There is nothing about consciousness as such that is particularly perplexing; it’s not like the quantum world or the behavior of schizophrenics. On the contrary, much of consciousness is well known to us and not a source of puzzlement (we don’t wake up every morning and feel bemused about our consciousness). Consciousness is only a major problem in relation to the brain, and only because of the “explanatory gap”. The problem is how the brain could produce consciousness (if “produce” is the right word): so, it is really a problem about the brain. We should be speaking of “the hard problem of the brain”, i.e., the problem of how the brain contrives to generate consciousness. We can explain how the brain produces behavior (more or less), but we can’t explain how it produces conscious experience. It is the mind-brain problem that is hard. But is there any easy part of that problem? Don’t say, “Yes, because explaining behavior is (relatively) easy”; that isn’t an aspect of the mind-body problem. I suggest that there are no easy explanatory mind-body problems to speak of; all the problems are hard. True, it is relatively easy to establish psychophysical correlations and psychophysical causation, but these are not explanatory problems. Nothing about consciousness is explained by brain science: not its subjectivity, not its intentionality, not its rationality, not even its propositionality. So, there are no easy mind-body problems of an explanatory nature—though there are easy behavior-body problems. There are, however, easy problems of consciousness: its general characterization (“there’s something it’s like”), its contents at a given moment, who has it and when, its various types (perception, thought, emotion, sensation, etc.). It is therefore quite misleading to say baldly that consciousness is a hard problem; or that some parts of the mind-body problem are easy. Some (most?) of consciousness is easy, and all forms of the mind-body problem are hard. We do better to speak of easy and hard problems of the brain: behavior easy, experience hard. Also, we should not give the impression that only the conscious part of the mind raises a hard mind-body problem; the unconscious mind raises one too.[1] All in all, the usual way of talking these days is massively misleading and should be abandoned.

There are other defects in the received terminology. First, it is too dichotomous: we are offered a two-way distinction between easy and hard problems. But surely, we need finer distinctions than that: we need really easy problems, easy-ish problems, pretty hard problems, hard problems, super hard problems, and terminally hard problems. Difficulty clearly comes in degrees and is not binary affair. Maybe the various mind-body problems vary in their degree of hardness, while all being pretty damn hard. Second, the standard talk makes no allowance for the possibility of subject-relative hardness:  perhaps no problem is hard simpliciter but only hard for this or that form of intelligence. Then we should speak of the “hard-for-us problem of X”. Third, the use of “hard” here fails to signal an essential feature of the type of problem it purports to describe, namely that the thing in question is a mystery. When Chomsky first introduced the division of question types into two kinds he spoke of “problems” and “mysteries”, not of “easy” and “hard” problems. This avoids suggesting that serious scientific questions are easy to answer, and it signaled that some questions move into a region beyond the merely “hard”: these questions completely baffle us, are difficult even to formulate, and suggest no workable methodology for their eventual solution. The word “mystery” captures this category of questions perfectly.

A question seldom asked by those who favor the “easy-hard” terminology is whether it generalizes beyond the case of the mind-body problem. I would say yes (though preferring the “problem-mystery” terminology). There are easy problems of matter and hard problems of matter: how to calculate a trajectory is easy, understanding quantum theory is hard. And there are other problems in physics that deserve to be called hard, which have been discussed elsewhere.[2] There are also hard problems in biology, notably the origin of life on earth, compared to easy problems (what species humans evolved from, for example). Some fall between these extremes, like the question of why sex evolved (this one might be categorized as “surprisingly hard”). Then we have moral problems: it is easy to see that one ought to return what one has borrowed but hard to decide what we owe to future generations. Again, we must avoid binary thinking and allow for all manner of gradations and varieties of difficulty, but it is certainly helpful to rank outstanding problems on a scale of hardness. I myself think that intentionality is an easier problem than subjectivity, though both are up there in degree of difficulty. The simple “easy-hard” distinction is really a way to avoid serious thinking not an example of it. Like many a catchy label, it hampers rather than helps.[3]

Colin McGinn

[1] See my paper “The Mystery of the Unconscious” in Philosophical Provocations (2017).

[2] See my Basic Structures of Reality (2011) and We Have No Idea, by Jorge Cham and Daniel Whiteson (2018).

[3] It is true that in “Can We solve the Mind-Body Problem?” I described consciousness as the “hard nut of the mind-body problem”, but I never subscribed to the “easy-hard” distinction as it came to be formulated subsequently. Nor did I ever use the phrase “the hard problem of consciousness”.