rifies_ the concept, proves its function of knowing that percept
to be true, but the percept's existence as the terminus of the chain of
intermediaries _creates_ the function. Whatever terminates that chain
was, because it now proves itself to be, what the concept 'had in mind.'

The towering importance for human life of this kind of knowing lies in
the fact that an experience that knows another can figure as its
_representative_, not in any quasi-miraculous 'epistemological' sense,
but in the definite practical sense of being its _substitute_ in various
operations, sometimes physical and sometimes mental, which lead us to
its associates and results. By experimenting on our ideas of reality, we
may save ourselves the trouble of experimenting on the real experiences
which they severally mean. The ideas form related systems, corresponding
point for point to the systems which the realities form; and by letting
an ideal term call up its associates systematically, we may be led to a
terminus which the corresponding real term would have led to in case we
had operated on the real world. And this brings us to the general
question of substitution.

IV. SUBSTITUTION

In Taine's brilliant book on 'Intelligence,' substitution was for the
first time named as a cardinal logical function, though of course the
facts had always been familiar enough. What, exactly, in a system of
experiences, does the 'substitution' of one of them for another mean?

According to my view, experience as a whole is a process in time,
whereby innumerable particular terms lapse and are superseded by others
that follow upon them by transitions which, whether disjunctive or
conjunctive in content, are themselves experiences, and must in general
be accounted at least as real as the terms which they relate. What the
nature of the event called 'superseding' signifies, depends altogether
on the kind of transition that obtains. Some experiences simply abolish
their predecessors without continuing them in any way. Others are felt
to increase or to enlarge their meaning, to carry out their purpose, or
to bring us nearer to their goal. They 'represent' them, and may fulfil
their function better than they fulfilled it themselves. But to 'fulfil
a function' in a world of pure experience can be conceived and defined
in only one possible way. In such a world transitions and arrivals (or
terminations) are the only events that happen, though they happen by so
many sor