Love, in animals, has not for its only object animals of the same species, but extends itself farther, and comprehends almost every sensible and thinking being. A dog naturally loves a man above his own species, and very commonly meets with a return of affection. As animals are but little susceptible either of the pleasures or pains of the imagination, they can judge of objects only by the sensible good or evil which they produce, and from _that_ must regulate their affections towards them. Accordingly we find, that by benefits or injuries we produce their love or hatred; and that, by feeding and cherishing any animal, we quickly acquire his affections; as by beating and abusing him we never fail to draw on us his enmity and ill-will. Love in beasts is not caused so much by relation as in our species; and that because their thoughts are not so active as to trace relations, except in very obvious instances. Yet 'tis easy to remark, that on some occasions it has a considerable influence upon them. Thus, acquaintance, which has the same effect as relation, always produces love in animals, either to men or to each other. For the same reason, any likeness among them is the source of affection. An ox confined to a park with horses, will naturally join their company, if I may so speak, but always leaves it to enjoy that of his own species, where he has the choice of both. The affection of parents to their young proceeds from a peculiar instinct in animals, as well as in our species. 'Tis evident that _sympathy_, or the communication of passions, takes place among animals, no less than among men. Fear, anger, courage, and other affections, are frequently communicated from one animal to another, without their knowledge of that cause which produced the original passion. Grief likewise is received by sympathy, and produces almost all the same consequences, and excites the same emotions, as in our species. The howlings and lamentations of a dog produce a sensible concern in his fellows. And 'tis remarkable, that though almost all animals use in play the same member, and nearly the same action as in fighting; a lion, a tiger, a cat, their paws; an ox, his horns; a dog, his teeth; a horse, his heels: yet they most carefully avoid harming their companion, even though they have nothing to fear from his resentment; which is an evident proof of the sense brutes have of each other's pain and pleasure. Every one has observed how much more dogs are animated when they hunt in a pack, than when they pursue their game apart; and 'tis evident this can proceed from nothing but from sympathy. 'Tis also well known to hunters, that this effect follows in a greater degree, and even in too great a degree, where too packs that are strangers to each other are joined together. We might, perhaps, be at a loss to explain this phenomenon, if we had not experience of a similar in ourselves.