ill, being moved
thereto by a stimulus which may be indicated by saying that it is the
spoken-word-constituting-a-commission-now-completed-and-entitling-me-
to-compensation. That is, the stimulus cannot be pushed back and
anchored at a fixed point in the past, but is a present factor at the
moment of response and is operative by virtue of its anticipation of
future events.

If, then, psychology is to be regarded as a study of behavior, it is
plainly necessary to reinterpret the category of behavior. For example,
a purely mechanical response to a light-stimulus may properly be viewed
as response to the ether-vibration or wave-length upon which it follows
in temporal sequence. But if this stimulation results in what is
commonly called consciousness, a different kind of response ensues. The
light-stimulus becomes a cause or occasion for the act of looking. But
why look, unless it be to secure a new stimulus for further response? We
stop to look, precisely because the first stimulus does not run smoothly
off the reel. The response will not go forward, but is halted and
expends itself in the effort to secure a further stimulus. This is the
moment of attention, in which the stimulus undergoes a process of
transformation, concomitantly with the process of reorganization in the
motor responses, and in the direction of ends or results that are
foreshadowed in it. This change in the stimulus takes place under
certain specifiable conditions, and the study of these conditions is a
study of such processes as perceiving, attending, remembering, and
deliberating, which are distinctively psychological in their nature.
Processes of this kind, if taken as changes in stimuli, find an
objective criterion in the adaptive behavior for the sake of which they
occur, and they provide psychology with a distinctive task and
subject-matter.

As against the introspectionist, then, the behaviorist is justified in
his contention that psychological procedure must be objective and
experimental in character. The danger to which he has exposed himself
is the failure to differentiate his problem from that of physiology and
physics. It is only by a proper recognition of both the objective and
the distinctive character of conscious behavior that psychology can free
itself of the reproach which is heaped upon it by members of its own
household and take the place that rightfully belongs to it in the
community of the sciences.

IV

According to the pre