ound by saying, "I thought it was nothing but my fancy"? Even healthy
persons are much more liable to both visual and auditory spectra--that
is, ideas of vision and sound so vivid that they are taken for new
impressions--than is commonly supposed; and, in some diseased states,
ideas of sensible objects may assume all the vividness of reality.

If ideas are nothing but copies of impressions, arranged, either in the
same order as that of the impressions from which they are derived, or in
a different order, it follows that the ultimate analysis of the contents
of the mind turns upon that of the impressions. According to Hume,
these are of two kinds: either they are impressions of sensation, or
they are impressions of reflection. The former are those afforded by the
five senses, together with pleasure and pain. The latter are the
passions or the emotions (which Hume employs as equivalent terms). Thus
the elementary states of consciousness, the raw materials of knowledge,
so to speak, are either sensations or emotions; and whatever we discover
in the mind, beyond these elementary states of consciousness, results
from the combinations and the metamorphoses which they undergo.

It is not a little strange that a thinker of Hume's capacity should have
been satisfied with the results of a psychological analysis which
regards some obvious compounds as elements, while it omits altogether a
most important class of elementary states.

With respect to the former point, Spinoza's masterly examination of the
Passions in the third part of the _Ethics_ should have been known to
Hume.[20] But, if he had been acquainted with that wonderful piece of
psychological anatomy, he would have learned that the emotions and
passions are all complex states, arising from the close association of
ideas of pleasure or pain with other ideas; and, indeed, without going
to Spinoza, his own acute discussion of the passions leads to the same
result,[21] and is wholly inconsistent with his classification of those
mental states among the primary uncompounded materials of consciousness.

If Hume's "impressions of reflection" are excluded from among the
primary elements of consciousness, nothing is left but the impressions
afforded by the five senses, with pleasure and pain. Putting aside the
muscular sense, which had not come into view in Hume's time, the
questions arise whether these are all the simple undecomposable
materials of thought? or whether others ex