[Footnote 15.  No questions in philosophy are more difficult, than when a number of causes present themselves for the same phaenomenon, to determine which is the principal and predominant.  There seldom is any very precise argument to fix our choice, and men must be contented to be guided by a kind of taste or fancy, arising from analogy, and a comparison of familiar instances.  Thus, in the present case, there are, no doubt, motives of public interest for most of the rules, which determine property; but still I suspect, that these rules are principally fixed by the imagination, or the more frivolous properties of our thought and conception.  I shall continue to explain these causes, leaving it to the reader’s choice, whether he will prefer those derived from publick utility, or those derived from the imagination.  We shall begin with the right of the present possessor.

It is a quality, which I have already observed in human nature, that when two objects appear in a close relation to each other, the mind is apt to ascribe to them any additional relation, in order to compleat the union; and this inclination is so strong, as often to make us run into errors (such as that of the conjunction of thought and matter) if we find that they can serve to that purpose.  Many of our impressions are incapable of place or local position; and yet those very impressions we suppose to have a local conjunction with the impressions of sight and touch, merely because they are conjoined by causation, and are already united in the imagination.  Since, therefore, we can feign a new relation, and even an absurd one, in order to compleat any union, it will easily be imagined, that if there be any relations, which depend on the mind, it will readily conjoin them to any preceding relation, and unite, by a new bond, such objects as have already an union in the fancy.  Thus for instance, we never fail, in our arrangement of bodies, to place those which are resembling in contiguity to each other, or at least in correspondent points of view; because we feel a satisfaction in joining the relation of contiguity to that of resemblance, or the resemblance of situation to that of qualities.  And this is easily accounted for from the known properties of human nature.  When the mind is determined to join certain objects, but undetermined in its choice of the particular objects, It naturally turns its eye to such as are related together.  They are already united in the mind:  They present themselves at the same time to the conception; and instead of requiring any new reason for their conjunction, it would require a very powerful reason to make us over-look this natural affinity.  This we shall have occasion to explain more fully afterwards, when we come to treat of beauty.  In the mean time, we may content ourselves with observing, that the same love of order and uniformity, which arranges the books in a library, and the chairs in a parlour, contribute to the formation