T 2.2.12.3

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.