Now looking back to our discussion of 43), we see that it was no
final || real explanation of B's being guided by
the signs when we said that B was guided if he
could also
have carried out orders consisting in other combinations of dots and
dashes than those of 43).
In fact, when we considered the question whether B in 43) was
guided by the signs, we were all the time inclined to say some such thing
as that we could only decide this question with certainty if we could
look into the actual mechanism connecting seeing the signs with acting
according to them.
For we have a definite picture of what in a mechanism we should call
certain parts being guided by others.
In fact, the mechanism which immediately suggests itself when we wish
to show what in such a case as 43) we should call “being
guided by the signs” is a mechanism of the type of a
pianola.
Here, in the working of the pianola we have a clear case of certain
act
ions,
66.
those of the
hammers of the piano, being guided by the pattern of holes in the pianola
roll.
We could use the expression, “The pianola is
reading off the record made by the perforations in the
roll”, and we might call patterns of such
perforations
complex signs or
sentences,
opposing their function in a pianola to the function which similar
devices have in mechanisms of a different type,
e.g., the combination of notches and teeth which
form a key bit.
The bolt of a lock is caused to slide by this particular combination,
but we should not say that the movement of the bolt was guided by the way
in which we combined teeth and notches, i.e., we
should not say that the bolt moved
according to the pattern of
the key bit.
You see here the connection between the idea of being guided and the
idea of being able to read new combinations of signs: for we should
say that the pianola
can read
any pattern of
perforations, of a particular kind, it is not built for one
particular tune or set of tunes (like a musical box), – –
whereas the bolt of the lock reacts to that pattern of the key bit only
which is predetermined
in || by the construction of the
lock.
We could say that the notches and teeth forming a key bit are not
comparable to the words making up a sentence but to the letters
making up a word, and that the pattern of the key bit in this sense
did not correspond to a complex sign, to a sentence, but to a
word.