Subsystems and Shared CodeTypical subsystems might be those that represent the people we know
intimately. They are represented in such a complex way in our brains that
their symbols enlarge to the rank of subsystem, becoming able to act
autonomously, making use of some resources in our brains for support. By
this, I mean that a subsystem symbolizing a friend can activate many of the
symbols in my brain just as I can. For instance, I can fire up my subsystem
for a good friend and virtually feel myself in his shoes, running through
thoughts which he might have, activating symbols in sequences which
reflect his thinking patterns more accurately than my own. It could be said
that my model of this friend, as embodied in a subsystem of my brain,
constitutes my own chunked description of his brain.
Does this subsystem include, then, a symbol for every symbol which I
think is in his brain? That would be redundant. Probably the subsystem
makes extensive use of symbols already present in my brain. For instance,
the symbol for "mountain" in my brain can be borrowed by the subsystem,
when it is activated. The way in which that symbol is then used by the
subsystem will not necessarily be identical to the way it is used by my full
brain. In particular, if I am talking with my friend about the Tien Shan
mountain range in Central Asia (neither of us having been there), and I
know that a number of years ago he had a wonderful hiking experience in
the Alps, then my interpretation of his remarks will be colored in part by
my imported images of his earlier Alpine experience, since I will be trying
to imagine how he visualizes the area.
In the vocabulary we have been building up in this Chapter, we could
say that the activation of the "mountain" symbol in me is under control of
my subsystem representing him. The effect of this is to open up a different
window onto to my memories from the one which I normally use-namely,
my "default option" switches from the full range of my memories to the set
of my memories of his memories. Needless to say, my representations of his
memories are only approximations to his actual memories, which are com-
plex modes of activation of the symbols in his brain, inaccessible to me.
My representations of his memories are also complex modes of activa-
tion of my own symbols-those for "primordial" concepts, such as grass,
trees, snow, sky, clouds, and so on. These are concepts which I must assume
are represented in him "identically" to the way they are in me. I must also
assume a similar representation in him of even more primordial notions:
the experiences of gravity, breathing, fatigue, color, and so forth. Less
primordial but perhaps a nearly unhersal human quality is the enjoyment
of reaching a summit and seeing a view. Therefore, the intricate processes
in my brain which are responsible for this enjoyment can be taken over
directly by the friend-subsystem without much loss of fidelity.
We could go on to attempt to describe how I understand an entire tale
told by my friend, a tale filled with many complexities of human relation-
ships and mental experiences. But our terminology would quickly become
inadequate. There would be tricky recursions connected with representa-
·386 Minds and Thoughts