We may begin with considering a-new the nature and force of sympathy.  The minds of all men are similar in their feelings and operations; nor can any one be actuated by any affection, of which all others are not, in some degree, susceptible.  As in strings equally wound up, the motion of one communicates itself to the rest; so all the affections readily pass from one person to another, and beget correspondent movements in every human creature.  When I see the effects of passion in the voice and gesture of any person, my mind immediately passes from these effects to their causes, and forms such a lively idea of the passion, as is presently converted into the passion itself.  In like manner, when I perceive the causes of any emotion, my mind is conveyed to the effects, and is actuated with a like emotion.  Were I present at any of the more terrible operations of surgery, it is certain, that even before it begun, the preparation of the instruments, the laying of the bandages in order, the heating of the irons, with all the signs of anxiety and concern in the patient and assistants, would have a great effect upon my mind, and excite the strongest sentiments of pity and terror.  No passion of another discovers itself immediately to the mind.  We are only sensible of its causes or effects.  From these we infer the passion:  And consequently these give rise to our sympathy.

Our sense of beauty depends very much on this principle; and where any object has atendency to produce pleasure in its possessor, it is always regarded as beautiful; as every object, that has a tendency to produce pain, is disagreeable and deformed.  Thus the conveniency of a house, the fertility of a field, the strength of a horse, the capacity, security, and swift-sailing of a vessel, form the principal beauty of these several objects.  Here the object, which is denominated beautiful, pleases only by its tendency to produce a certain effect.  That effect is the pleasure or advantage of some other person.  Now the pleasure of a stranger, for whom we have no friendship, pleases us only by sympathy.  To this principle, therefore, is owing the beauty, which we find in every thing that is useful.  How considerable a part this is of beauty can easily appear upon reflection.  Wherever an object has a tendency to produce pleasure in the possessor, or in other words, is the proper cause of pleasure, it is sure to please the spectator, by a delicate sympathy with the possessor.  Most of the works of art are esteemed beautiful, in proportion to their fitness for the use of man, and even many of the productions of nature derive their beauty from that source.  Handsome and beautiful, on most occasions, is nor an absolute but a relative quality, and pleases us by nothing but its tendency to produce an end that is agreeable.