that this feat could be accomplished by "juggling"-that is, by the single
class symbol Hitting back and forth between several different modes of
activation (one for each person).
Between the extremes, there must be room for many sorts of inter-
mediate cases. There may be a whole hierarchy of ways of creating the
class-instance distinction in the brain, giving rise to symbols-and symbol-
organizations-of varying degrees of specificity. The following different
kinds of individual and joint activation of symbols might be responsible for
mental images of various degrees of specificity:
(1) various different modes or depths of activation of a single
class symbol;
(2) simultaneous activation of several class symbols in some
coordinated manner;
(3) activation of a single instance symbol;
(4) activation of a single instance symbol In conjunction with
activation of several class symbols;
(5) simultaneous activation of several instance symbols and sev-
eral class symbols in some coordinated manner.This brings us right back to the question: "When is a symbol a distin-
guishable subsystem of the brain?" For instance, consider the second
example-simultaneous activation of several class symbols in some coordi-
nated manner. This could easily be what happens when "piano sonata" is
the concept under consideration (the symbols for "piano" and "sonata"
being at least two of the activated symbols). But if this pair of symbols gets
activated in conjunction often enough, it is reasonable to assume that the
link between them will become strong enough that they will act as a unit,
when activated together in the proper way. So two or more symbols can act
as one, under the proper conditions, which means that the problem of
enumerating the number of symbols in the brain is trickier than one might
guess.
Sometimes conditions can arise where two previously unlinked sym-
bols get activated simultaneously and in a coordinated fashion. They may
fit together so well that it seems like an inevitable union, and a single new
symbol is formed by the tight interaction of the two old symbols. If this
happens, would it be fair to say that the new symbol "always had been there
but never had been activated"-or should one say that it has been
"created"?
In case this sounds too abstract, let us take a concrete example: the
Dialogue Crab Canon. In the invention of this Dialogue, two existing
symbols-that for "musical crab canon", and that for "verbal dialogue"-
had to be activated simultaneously and in some way forced to interact.
Once this was done, the rest was quite inevitable: a new symbol-a class
symbol-was born from the interaction of these two, and from then on it
was able to be activated on its own. Now had it always been a dormant
symbol in my brain? If so, then it must also have been a dormant symbol in
Brains and Thoughts^355