Post. i.). From the
foregoing proposition it is evident that, whenever the mind is
afterwards affected by the former, through its true cause, which
(by hypothesis) neither increases nor diminishes its power of
action, it will be at the same time affected by the latter, which
does increase or diminish its power of activity, that is (III.
xi. note) it will be affected with pleasure or pain. Thus the
former of the two emotions will, not through itself, but
accidentally, be the cause of pleasure or pain. In the same way
also it can be easily shown, that a thing may be accidentally the
cause of desire. Q.E.D.

Corollary.--Simply from the fact that we have regarded a thing
with the emotion of pleasure or pain, though that thing be not
the efficient cause of the emotion, we can either love or hate
it.

Proof.--For from this fact alone it arises (III. xiv.), that
the mind afterwards conceiving the said thing is affected with
the emotion of pleasure or pain, that is (III. xi. note),
according as the power of the mind and body may be increased or
diminished, &c.; and consequently (III. xii.), according as the
mind may desire or shrink from the conception of it (III. xiii.
Coroll.), in other words (III. xiii. note), according as it may
love or hate the same. Q.E.D.

Note.--Hence we understand how it may happen, that we love or
hate a thing without any cause for our emotion being known to us;
merely, as a phrase is, from sympathy or antipathy. We should
refer to the same category those objects, which affect us
pleasurably or painfully, simply because they resemble other
objects which affect us in the same way. This I will show in the
next Prop. I am aware that certain authors, who were the first
to introduce these terms "sympathy" and "antipathy," wished to
signify thereby some occult qualities in things; nevertheless I
think we may be permitted to use the same terms to indicate known
or manifest qualities.

PROP. XVI. Simply from the fact that we conceive, that a given
object has some point of resemblance with another object which is
wont to affect the mind pleasurably or painfully, although the
point of resemblance be not the efficient cause of the said
emotions, we shall still regard the first--named object with love
or hate.

Proof.--The point of resemblance was in the object (by
hypothesis), when we regarded it with pleasure or pain, thus
(III. xiv.), when the mind is affected by the image thereof, it
will