ght, an emotion
involves a confused perception of its external stimulus. This follows
from what was said in Lecture VII. We there defined a perception as an
appearance, however irregular, of one or more objects external to the
brain. And in order to be an appearance of one or more objects, it is
only necessary that the occurrence in question should be connected
with them by a continuous chain, and should vary when they are varied
sufficiently. Thus the question whether a mental occurrence can be
called a perception turns upon the question whether anything can be
inferred from it as to its causes outside the brain: if such inference
is possible, the occurrence in question will come within our definition
of a perception. And in that case, according to the definition in
Lecture VIII, its non-mnemic elements will be sensations. Accordingly,
whether emotions are caused by changes in the viscera or by sensible
objects, they contain elements which are sensations according to our
definition.

An emotion in its entirety is, of course, something much more complex
than a perception. An emotion is essentially a process, and it will be
only what one may call a cross-section of the emotion that will be a
perception, of a bodily condition according to James, or (in certain
cases) of an external object according to his opponents. An emotion in
its entirety contains dynamic elements, such as motor impulses, desires,
pleasures and pains. Desires and pleasures and pains, according to the
theory adopted in Lecture III, are characteristics of processes, not
separate ingredients. An emotion--rage, for example--will be a certain
kind of process, consisting of perceptions and (in general) bodily
movements. The desires and pleasures and pains involved are properties
of this process, not separate items in the stuff of which the emotion
is composed. The dynamic elements in an emotion, if we are right in our
analysis, contain, from our point of view, no ingredients beyond those
contained in the processes considered in Lecture III. The ingredients
of an emotion are only sensations and images and bodily movements
succeeding each other according to a certain pattern. With this
conclusion we may leave the emotions and pass to the consideration of
the will.

The first thing to be defined when we are dealing with Will is a
VOLUNTARY MOVEMENT. We have already defined vital movements, and we have
maintained that, from a behaviourist standpoint, it is im