ore by means of a regular
series of subordinate actions beginning and ending at a certain tolerably
well-defined point--as when Herr Joachim plays a sonata in public, or
when we dress or undress ourselves; and actions the details of which are
indeed guided by memory, but which in their general scope and purpose are
new--as when we are being married, or presented at court.

At each point in any action of the first of the two kinds above referred
to there is a memory (conscious or unconscious according to the less or
greater number of times the action has been repeated), not only of the
steps in the present and previous performances which have led up to the
particular point that may be selected, _but also of the particular point
itself_; there is therefore, at each point in a habitual performance, a
memory at once of like antecedents _and of a like present_.

If the memory, whether of the antecedent or the present, were absolutely
perfect; that is to say, if the vibrations in the nervous system (or, if
the reader likes it better, if the molecular change in the particular
nerves affected--for molecular change is only a change in the character
of the vibrations going on within the molecules--it is nothing else than
this)--it the vibrations in the particular nerves affected by any
occurrence continued on each fresh repetition of the occurrence in their
full original strength and without having been interfered with by any
other vibrations; and if, again, the new waves running into the faint old
ones from exterior objects and restoring the lapsed molecular state of
the nerves to a pristine condition were absolutely identical in character
on each repetition of the occurrence with the waves that ran in upon the
last occasion, then there would be no change in the action, and no
modification or improvement could take place. For though indeed the
latest performance would always have one memory more than the latest but
one to guide it, yet the memories being identical, it would not matter
how many or how few they were.

On any repetition, however, the circumstances, external or internal, or
both, never are absolutely identical: there is some slight variation in
each individual case, and some part of this variation is remembered, with
approbation or disapprobation as the case may be.

The fact, therefore, that on each repetition of the action there is one
memory more than on the last but one, and that this memory is slightly
diff