symbols for other people who are less familiar but who have something in
common with Palindromi, and for whom he can serve as a temporary
stereotype, until you acquire more information, enabling the new symbols
also to become autonomous.The Difficulty of Disentangling Symbols from Each OtherThese stages of growth and eventual detachment of an instance from a
class will be distinguishable from each other by the way in which the
symbols involved are linked. Sometimes it will no doubt be very difficult to
tell just where one symbol leaves off and the other one begins. How "active"
is the one symbol, compared to the other? If one can be activated indepen-
dently of the other, then it would he quite sensible to call them autono-
mous.
We have used an astronomy metaphor above, and it is interesting that
the problem of the motion of planets is an extremely complex one-in fact
the general problem of three gravitationally interacting bodies (such as the
Earth, Moon, and Sun) is far from solved, even after several centuries of
work. One situation in which it is possible to obtain good approximate
solutions, however, is when one body is much more massive than the other
two (here, the Sun); then it makes sense to consider that body as stationary,
with the other two rotating about it; on top of this can finally be added the
interaction between the two satellites. But this approximation depends on
breaking up the system into the Sun, and a "cluster": the Earth-Moon
system. This is an approximation, but it enables the system to be under-
stood quite deeply. So to what extent is this cluster a part of reality, and to
what extent is it a mental fabrication, a human imposition of structure on
the universe? This problem of the "reality" of boundaries drawn between
what are perceived to be autonomous or semi-autonomous clusters will
create endless trouble when we relate it to symbols in the brain.
One greatly puzzling question is the simple issue of plurals. How do we
visualize, say, three dogs in a teacupr Or several people in an elevator? Do
we begin with the class symbol for "dog" and then rub three "copies" off of
it? That is, do we manufacture three fresh instance symbols using the class
symbol "dog" as template? Or do we jointly activate the symbols "three" and
"dog"? By adding more or less detail to the scene being imagined, either
theory becomes hard to maintain. For instance, we certainly do not have a
separate instance symbol for each nose, mustache, grain of salt, etc., that we
have ever seen. We let class symbols take care of such numerous items, and
when we pass people on the street who have mustaches, we somehow just
activate the "mustache" class symbol, without minting fresh instance sym-
bols, unless we scrutinize them carefully.
On the other hand, once we begin to distinguish individuals, we cannot
rely on a single class symbol (e.g., "person") to timeshare itself among all
the different people. Clearly there must come into existence separate
instance symbols for individual people. It would be ridiculous to imagine(^354) Brains and Thoughts