1996-12-20: Kinds of Minds

Kinds of Minds (1996)

by Daniel Dennett (1942-)

This book seems to be a side trip for Dennett, and also seems to have received less care than his primary interest (which I take to be the nature of consciousness). The main thrust is to characterize the kinds of minds that might exist, and to contrast them with the kind of mind humans have.

Dennett begins with generalities, and motivation for this excursion. He says:

What kinds of minds are there? And how do we know? The first question is about what exists – about ontology, in philosophical parlance; the second question is about our knowledge – about epistemology. The goal of this book is not to answer these two questions once and for all, but rather to show why these questions have to be answered together. Philosophers often warn against confusing ontological questions with epistemological questions. What exists is one thing, they say, and what we can know about it is something else. There may be things that are completely unknowable to us, so we must be careful not to treat the limits of our knowledge as sure guides to the limits of what there is. I agree that this is good general advice, but I will argue that we already know enough about minds to know that one of the things that makes them different from everything else in the universe is the way we know about them. For instance, you know you have a mind and you know you have a brain, but these are different kinds of knowledge. You know you have a brain the way you know you have a spleen: by hearsay. You’ve never seen your spleen or your brain (I would bet), but since the textbooks tell you that all normal human beings have one of each, you conclude that you almost certainly have one of each as well. You are more intimately acquainted with your mind – so intimately that you might even say that you are your mind. (That’s what Descartes said: he said he was a mind, a res cogitans, or thinking thing.) A book or a teacher might tell you what a mind is, but you wouldn’t have to take anybody’s word for the claim that you had one. If it occurred to you to wonder whether you were normal and had a mind as other people do, you would immediately realize, as Descartes pointed out, that your very wondering this wonder demonstrated beyond all doubt that you did indeed have a mind.

Eventually he constructs a tower of minds, which he calls the Tower of Generate-and-Test. (He also tries to forestall criticism by saying it is outrageously oversimplified.)

In the beginning, there was Darwinian evolution of species by natural selection. A variety of candidate organisms were blindly generated, by more or less arbitrary processes of recombination and mutation of genes. These organisms were field-tested, and only the best designs survived. This is the ground floor of the tower. Let us call its inhabitants Darwinian creatures. …

Eventually, among its novel creations were some designs with the property of phenotypic plasticity: that is, the individual candidate organisms were not wholly designed at birth; there were elements of their design that could be adjusted by events that occurred during the field tests. Some of these candidates . . . were fortunate enough to have wired-in “reinforcers” that happened to favor Smart Moves – that is, actions that were better for the candidates than the available alternative actions. . . . Only those fortunate enough to be born with appropriate reinforcers would have an advantage. We may call this subset of Darwinian creatures Skinnerian creatures, since, as the behaviorist psychologist B. F. Skinner was fond of pointing out, such “operant conditioning” is not just analogous to Darwinian natural selection; it is an extension of it. …

Skinnerian conditioning is a good thing as long as you are not killed by one of your early errors. A better system involves preselection among all possible behaviors or actions, so that the truly stupid moves are weeded out before they’re hazards in “real life.” We may call the beneficiaries of this third floor in the Tower Popperian creatures, since, as the philosopher Sir Karl Popper once elegantly put it, this design enhancement “permits our hypotheses to die in our stead.” Unlike the merely Skinnerian creatures, many of whom survive only because they make lucky first moves, Popperian creatures survive because they are smart enough to make better-than-chance first moves. Of course, they’re just lucky to be so smart, but that’s better than being just lucky. …

Once we get to Popperian creatures – creatures whose brains have the potential to be endowed, in inner environments, with preselective prowess – what happens next? Many different things, no doubt, but we will concentrate on one particular innovation whose powers we can clearly see. Among the successors to mere Popperian creatures are those whose inner environments are informed by the designed portions of the outer environment. One of Darwin’s fundamental insights is that design is expensive but copying designs is cheap; that is, making an all new design is very difficult, but redesigning old designs is relatively easy. Few of us could reinvent the wheel, but we don’t have to, since we acquired the wheel design (and a huge variety of others) from the cultures we grew up in. We may call this sub-sub-subset of Darwinian creatures Gregorian creatures, since the British psychologist Richard Gregory is to my mind the preeminent theorist of the role of information (or more exactly, what Gregory calls Potential Intelligence) in the creation of Smart Moves (or what Gregory calls Kinetic Intelligence). Gregory observes that a pair of scissors, as a well-designed artifact, is not just a result of intelligence, but an endower of intelligence (external potential intelligence), in a very straightforward and intuitive sense: when you give someone a pair of scissors, you enhance their potential to arrive more safely and swiftly at Smart Moves.

The book is less than fully satisfying. It seems to have been rather hastily assembled from notes for lectures given only once. Nonetheless, it is probably worth reading for those with a strong interest in Dennett’s work. Like any worthwhile book, this one contains some interesting epigrams:

Nature appears to have built the apparatus of rationality not just on top of the apparatus of biological regulation, but also from it and with it. – Antonio Damasio, Descartes’ Error: Emotion, Reason, and the Human Brain

Language was invented so that people could conceal their thoughts from each other. – Charles-Maurice de Talleyrand

Just as you cannot do very much carpentry with your bare hands, there is not much thinking you can do with your bare brain. – Bo Dahlbom and Lars-Erik Janlert, Computer Future

If the untrained infant’s mind is to become an intelligent one, it must acquire both discipline and initiative. – Alan Turing

The heart-stopping thing about the new-born is that, from minute one, there is somebody there. Anyone who bends over the cot and gazes at it is being gazed back at. …

Once the child has learned the meaning of “why” and “because,” he has become a fully paid-up member of the human race. – Elaine Morgan, The Descent of the Child: Human Evolution from a New Perspective

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