esent lecture I have nothing original to
say, and I am treating them only in order to complete the discussion of
my main thesis, namely that all psychic phenomena are built up out of
sensations and images alone.

Emotions are traditionally regarded by psychologists as a separate
class of mental occurrences: I am, of course, not concerned to deny
the obvious fact that they have characteristics which make a special
investigation of them necessary. What I am concerned with is the
analysis of emotions. It is clear that an emotion is essentially
complex, and we have to inquire whether it ever contains any
non-physiological material not reducible to sensations and images and
their relations.

Although what specially concerns us is the analysis of emotions, we
shall find that the more important topic is the physiological causation
of emotions. This is a subject upon which much valuable and exceedingly
interesting work has been done, whereas the bare analysis of emotions
has proved somewhat barren. In view of the fact that we have defined
perceptions, sensations, and images by their physiological causation, it
is evident that our problem of the analysis of the emotions is bound up
with the problem of their physiological causation.

Modern views on the causation of emotions begin with what is called
the James-Lange theory. James states this view in the following terms
("Psychology," vol. ii, p. 449):

"Our natural way of thinking about these coarser emotions, grief, fear,
rage, love, is that the mental perception of some fact excites the
mental affection called the emotion, and that this latter state of mind
gives rise to the bodily expression. My theory, on the contrary, is that
THE BODILY CHANGES FOLLOW DIRECTLY THE PERCEPTION OF THE EXCITING FACT,
AND THAT OUR FEELING OF THE SAME CHANGES AS THEY OCCUR _IS_ THE EMOTION
(James's italics). Common sense says: we lose our fortune, are sorry
and weep; we meet a bear, are frightened and run; we are insulted by
a rival, are angry and strike. The hypothesis here to be defended says
that this order of sequence is incorrect, that the one mental state is
not immediately induced by the other, that the bodily manifestations
must first be interposed between, and that the more rational statement
is that we feel sorry because we cry, angry because we strike, afraid
because we tremble, and not that we cry, strike, or tremble, because
we are sorry, angry, or fearful, as the case may be. Wit