reverie, where the trains connected with sensation are uninterrupted, are
more vivid and distinct than those of memory, so that they cannot be
distinguished by this criterion.

The very ingenious author of the Elements of Criticism has described what
he conceives to be a species of memory, and calls it ideal presence; but
the instances he produces are the reveries of sensation, and are therefore
in truth connections of the imagination, though they are recalled in the
order they were received.

The ideas connected by association are in common discourse attributed to
memory, as we talk of memorandum-rings, and tie a knot on our handkerchiefs
to bring something into our minds at a distance of time. And a school-boy,
who can repeat a thousand unmeaning lines in Lilly's Grammar, is said to
have a good memory. But these have been already shewn to belong to the
class of association; and are termed ideas of suggestion.

II. Lastly, the method already explained of classing ideas into those
excited by irritation, sensation, volition, or association, we hope will be
found more convenient both for explaining the operations of the mind, and
for comparing them with those of the body; and for the illustration and the
cure of the diseases of both, and which we shall here recapitulate.

1. Irritative ideas are those, which are preceded by irritation, which is
excited by objects external to the organs of sense: as the idea of that
tree, which either I attend to, or which I shun in walking near it without
attention. In the former case it is termed perception, in the latter it is
termed simply an irritative idea.

2. Sensitive ideas are those, which are preceded by the sensation of