JB: Let's talk some more about philosophers and epistemologists.

MINSKY: 'Philosopher' is a suitcase word. We use it both for those who make new theories and for those who teach the history of old theories. We use 'philosophy' for all sorts of theories about the natures of things and minds and values and kinds of arguments. I don't much like those words because their users too often emphasize pre-scientific theories of subjects that science has already further clarified. In fairness, though, philosophy suffers from the same "receding horizon" effect that plagues researchers in Artificial Intelligence. That is, whenever one of their problems gets solved, then it is absorbed by another, more practical profession, such as physics, psychology, engineering, or computer science. So philosophers are too often seen as impractical bumblers, because of being ahead of their time, and not getting credit for previous accomplishments.

JB: Can you explain your theory of emotions?

MINSKY: People often use that word to express the idea that there is some deep and essential difference between thinking and feeling. My view is that this is a bad mistake, because emotions are not alternatives to thinking; they are simply different types of thinking. I regard each emotional state to be a different arrangement or disposition of mental resources. Each uses some different combination of techniques or strategies for thinking.

For example, when you are afraid, the parts of your mind that select your goals are biased in a particular way. They assign the highest priority to avoiding certain kinds of things. Similarly, when you're hungry, this means high priorities on food-finding goals. Also, other systems suppress some of your long-range planning mechanisms-and that might contribute to what we describe as a sense of panic or urgency. Being afraid, or being hungry, then, are particular methods of thinking. Similarly, the feeling of pain results from the engagement of certain special resources. If something happens to pinch your toe, then that part of your body gets highest priority and your paramount goal is to finding ways to get rid of that activity. Presumably each common emotion involves arousing a variety of particular processes in different brain centers. These in turn will then affect how some other mental resources will be disposed.

Especially, those emotions affect your active selections of goals and plans. When you're in pain you find it hard to work on problems that take a long time. When we try to describe how it feels to hurt, we find it hard to say anything specific about the 'sensation' itself'-and that makes it seem inexpressible. However, it's all too easy to speak about how hurting alters how you think. It's easy to carry on endlessly about your frustration by being distracted from your other goals, your concern about not getting your work done, about how this will affect your dependencies and relationships, and your worries about its impact of your other future activities, and so on.

Now, a philosophical dualist might then complain: "You've described how hurting affects your mind-but you still can't express how hurting feels." This, I maintain, is a huge mistake-that attempt to reify 'feeling' as an independent entity, with an essence that's indescribable. As I see it, feelings are not strange alien things. It is precisely those cognitive changes themselves that constitute what 'hurting' is-and this also includes all those clumsy attempts to represent and summarize those changes. The big mistake comes from looking for some single, simple, 'essence' of hurting, rather than recognizing that this is the word we use for complex rearrangement of our disposition of resources.

Of course, this runs against the grain. Usually, when we see an object or hear a word, its 'meaning' seems simple and direct. So we usually expect to be able to describe things without having to construct and describe such complicated cognitive theories. This fictitious apparent simplicity of feelings is why, I think, most philosophers have been stuck for so long - except for a few folks like Aaron Sloman, John McCarthy and Daniel Dennett. When a mental condition seems hard to describe, this could be because the subject simply is more complicated that you thought. The way to get unstuck is to describe architectures with more details. Only then can we imagine how certain situations or stimuli could lead a brain into the activities that we recognize when we feel love or fear, or pain.

JB: Let's talk about the love machine.

MINSKY: One section of The Emotional Machine is about how people acquire new kinds of goals in the context of loving attachments. It seems to me very curious that this has not been a main concern of most theories about the structures of minds. The question of how people learn high-level goals is scarcely ever mentioned at all in most books about psychology.

How does a hungry animal learn new ways to achieve its food-finding goal? Obviously, it has to explore-and when it doesn't know what to do it has to explore, it has to try experiments. If it happens to press a certain lever, and then receives a bit of food, that makes some kind of impression on it. Later, when it is hungry again it will tend to press similar levers. We could summarize this by saying that our animal has learned a new way to achieve its original goal. It has learned that a good sub-goal for finding food is to find and press such a lever.

Most behaviorists studied how an animal with a goal could learn new sub-goals for that goal. But how do we acquire those original goals? In cases like hunger, the answer is clear: such goals can be built-in genetically. But how do people acquire new goals that aren't sub-goals of other goals? What could make you adopt a new goal-if it's not to subserve some other old goal.

It seems to me that this could be based on combining these two older schemes: the "imprinting" studied by Konrad Lorenz and the Oedipus complex of Sigmund Freud. In the 1920s Lorenz demonstrated that many infant animals develop a special 'attachment' to a parent. Much earlier Freud suggested that a human infant become attached to (or enamored of) one or more special persons-usually parents or caretakers-who then serve models for that child's future values and high-level goals. Clearly Freud was basically right, but we still need to ask how that process might work. How do those values get represented or 'introjected'?

My conjecture is that this process employs an adaptation of the ancient imprinting mechanism, which first evolved mainly to promote the offspring's physical safety. The baby animal becomes disturbed when not in the presence of the parent, and this serves to make it quickly learn behavior that makes it stay close by. In humans though, it seems to me, this mechanism later became involved with two new types of learning, whose activities we recognize as emotions called pride and shame.

I maintain that the type of learning connected with pride is used to establish new high-level goals-or what we call positive values. The point is that pride is only evoked when a child is praised by the a person to whom it's attached. So it's not quite the same as conventional "positive reinforcement"-which can only reinforce sub-goals. Similarly, if a child is scolded by an attachment person, then that child's current intentions acquire the negative character of a shameful taboo.

It would take too long to tell all the details-but I'll emphasize what is different here. I had started by thinking about how to design machines that could learn both goals and sub-goals. It took me some time to see that these might need several different architectures. The old idea of conditioning, working down from goal to sub-goal, needs only a way to recognize when one fails or succeeds to reach a goal. Values, however, need something else-some external source of selection. Then I noticed that this was just what Freud had addressed, in his various theories of infant attachment, and his models of aversion and censorship. My colleagues seem startled when I mention Freud-but I see him as one of the few psychologists who failed to fall prey to Physics Envy. Unlike most of the others, Freud was willing to suppose, when it seemed necessary, that the mind is composed of more than a few processes or compartments. Instead of making desperate and futile attempts to reduce the numbers of different assumptions, he was willing instead to imagine architectures with more structure-and then to face the difficulty of understanding the relations and interconnections. I see him as a pioneer of advanced computer science, very far ahead of his time, because he had of his many ideas about representations, aliases, censors, suppressors, and about types and structures of memory.