to migrate (as directed by thousands of different genes), and this results in thousands of bundles of links between those primordial clusters and clumps—and those ‘levels’ soon become indistinct.
This means that we cannot expect to precisely divide all the functions of brains into clear and separate mental levels. That would be as futile as to sharply define the borders between the seven seas. Instead, each of our social agencies divides the marine world in different ways for different and conflicting purposes, such as geophysical, ecological, and political. In the same way we’ll need to multiple models of brains, each to suit some different attempt to explain some kinds of mental phenomena. For example, we may turn out to need more elaborate theories about how self-conscious reflection works, if only because of its special importance to those concerned with religious, legal, and ethical questions.
This expresses a real dilemma: No system so complex as this could work without some ways to manage itself. Otherwise it would flail with no sense of direction—and would inanely skip from each thing to the next. On the other side, it would not make sense to locate all control in one single place, for than all would be lost from a single mistake. So the following chapters of this book will multiple ways in which our minds use multiple ways to control themselves, and we’ll come back to the “Self” in chapter §9.
While on the subject of central control, we should point out that Model Six could also be seen in terms of Sigmund Freud’s idea of the mind as a “sandwich” with three major parts.
Freud’s ‘Id’ consists of instinctive drives, while his ‘Superego’ embodies our learned ideals (many of which are inhibitions). The ‘Ego’ would then be those parts in between—the deliberate and reflective levels—whose principal, at least in Freud’s view, is to resolve the conflicts between our instincts and our acquired ideals. Then a person’s ego may represent itself as being in control of things—whereas a friend or psychiatrist may see that ego as a battlefield.
It would not surprise me if such a machine, after having acquired the right kinds of knowledge, were to declare that it as conscious as we claim to be. This sort of thing could happen if, as we’ll suggest in Chapter §9, its highest levels built models that represent its ‘Self’ as a single, self-aware entity. Of course, other entities might disagree.
This chapter began by asking how we could conceive of things that we’ve never seen or experienced. The rest of this chapter will show more details of how our imagination could result from multiple levels of processing.
§5-7. Imagination
“We don’t see things as they are. We see things as we are.”
When Carol picks up one of her blocks, that action seems utterly simple to her: she just reaches out, grasps it, and lifts it up. She just sees that block and knows how to act. No ‘thinking’ seems to intervene.
However, the seeming ‘directness’ of seeing the world is an illusion that comes from our failure to sense its complexity. For, most of what we think we see comes from our knowledge and from our imaginations. Thus, consider this portrait of Abraham Lincoln made by my old friend Leon Harmon, a pioneer in computerized graphics. (To the right is a portrait that I made of Leon.)
How do you recognize features in pictures so sparse that a nose or an eye is but three or four patches of darkness or light? Clearly, you do this by using additional knowledge. For example, when you sit at a table across from your friends, you cannot see their backs or legs—but your knowledge-based systems assume by default that all those body-parts are present. Thus we take our perceptual talents for granted—but ‘seeing’ seems simple only because the rest of our minds are virtually blind to the processes that we use to do it.
In 1965 it was our goal was to develop machines that could do some of the things that most children can do—such as pouring a liquid into a cup, or building arches and towers like this from disorderly clutters of building blocks.[80] To do this, we built a variety of mechanical hands and electronic eyes—and we connected these to our computer.
When we built that first robot for building with blocks, it made hundreds of different kinds of mistakes.[81] It would try to put blocks on top of themselves, or try to put two of them in the same place, because it did not yet have the commonsense knowledge one needs to manipulate physical objects! Even today, no one has yet made a visual system that behaves in anything close to humanlike ways to distinguish the objects in everyday visual scenes. But eventually, our army of students developed programs that could “see” arrangements of plain wooden blocks well enough to recognize that a structure like this is
It took several years for us to make a computer-based robot called
However, those low-level stages would frequently fail to find enough usable features. Look at this magnified digital view of the lower front edge of the top of that arch:
