In our common way of thinking we are placed in a kind of middle station betwixt the past and future; and as our imagination finds a kind of difficulty in running along the former, and a facility in following the course of the latter, the difficulty conveys the notion of ascent, and the facility of the contrary.  Hence we imagine our ancestors to be, in a manner, mounted above us, and our posterity to lie below us.  Our fancy arrives not at the one without effort, but easily reaches the other:  Which effort weakens the conception, where the distance is small; but enlarges and elevates the imagination, when attended with a suitable object.  As on the other hand, the facility assists the fancy in a small removal, but takes off from its force when it contemplates any considerable distance.

It may not be improper, before we leave this subject of the will, to resume, in a few words, all that has been said concerning it, in order to set the whole more distinctly before the eyes of the reader.  What we commonly understand by passion is a violent and sensible emotion of mind, when any good or evil is presented, or any object, which, by the original formation of our faculties, is fitted to excite an appetite.  By reason we mean affections of the very same kind with the former; but such as operate more calmly, and cause no disorder in the temper:  Which tranquillity leads us into a mistake concerning them, and causes us to regard them as conclusions only of our intellectual faculties.  Both the causes and effects of these violent and calm passions are pretty variable, and depend, in a great measure, on the peculiar temper and disposition of every individual.  Generally speaking, the violent passions have a more powerful influence on the will; though it is often found, that the calm ones, when corroborated by reflection, and seconded by resolution, are able to controul them in their most furious movements.  What makes this whole affair more uncertain, is, that a calm passion may easily be changed into a violent one, either by a change of temper, or of the circumstances and situation of the object, as by the borrowing of force from any attendant passion, by custom, or by exciting the imagination.  Upon the whole, this struggle of passion and of reason, as it is called, diversifies human life, and makes men so different not only from each other, but also from themselves in different times.  Philosophy can only account for a few of the greater and more sensible events of this war; but must leave all the smaller and more delicate revolutions, as dependent on principles too fine and minute for her comprehension.

SECT.  IX OF THE DIRECT PASSIONS

It is easy to observe, that the passions, both direct and indirect, are founded on pain and pleasure, and that in order to produce an affection of any kind, it is only requisite to present some good or evil.  Upon the removal of pain and pleasure there immediately follows a removal of love and hatred, pride and humility, desire and aversion, and of most of our reflective or secondary impressions.