As all the perceptions of the mind may
be divided into impressions and ideas, so the impressions admit of another
division into original and secondary. This division of the impressions is
the same with that which I formerly made use of when I distinguish'd them
int impressions of sensation and reflection. Original impressions or impressions
of sensation are such as without any anteceden perception arise in the soul,
from the constitution of the body, from the animal spirits, or from the
application of objects to the external organs. Secondary, or reflective
impressions are such as proceed from some of these original ones, either
immediately or by the interposition of its idea. Of the first kind are all
the impressions of the senses, and all bodily pains and pleasures: Of the
second are the passions, and other emotions resembling them.