* Various arguments in its favour are advanced by A.
Wohlgemuth, "On the feelings and their neural correlate,
with an examination of the nature of pain," "British Journal
of Psychology," viii, 4. (1917). But as these arguments are
largely a reductio ad absurdum of other theories, among
which that which I am advocating is not included, I cannot
regard them as establishing their contention.

** "Sensation and the Cerebral Cortex," "Brain," vol. xli,
part ii (September, 1918), p. 90. Cf. also Wohlgemuth, loc.
cit. pp. 437, 450.

"It is necessary at the outset to distinguish clearly between
'discomfort' and 'pain.' Pain is a distinct sensory quality equivalent
to heat and cold, and its intensity can be roughly graded according to
the force expended in stimulation. Discomfort, on the other hand,
is that feeling-tone which is directly opposed to pleasure. It may
accompany sensations not in themselves essentially painful; as for
instance that produced by tickling the sole of the foot. The reaction
produced by repeated pricking contains both these elements; for it
evokes that sensory quality known as pain, accompanied by a disagreeable
feeling-tone, which we have called discomfort. On the other hand,
excessive pressure, except when applied directly over some nerve-trunk,
tends to excite more discomfort than pain."

The confusion between discomfort and pain has made people regard
discomfort as a more substantial thing than it is, and this in turn has
reacted upon the view taken of pleasure, since discomfort and pleasure
are evidently on a level in this respect. As soon as discomfort is
clearly distinguished from the sensation of pain, it becomes more
natural to regard discomfort and pleasure as properties of mental
occurrences than to regard them as separate mental occurrences on their
own account. I shall therefore dismiss the view that they are separate
mental occurrences, and regard them as properties of such experiences as
would be called respectively uncomfortable and pleasant.

It remains to be examined whether they are actual qualities of such
occurrences, or are merely differences as to causal properties. I do not
myself see any way of deciding this question; either view seems equally
capable of accounting for the facts. If this is true, it is safer to
avoid the assumption that there are such intrinsic qualities of
mental occurrences as are in question, and to assume o