 They have no religion and their sole morality is the defence of reason, and so they are not particularly moved by pity or a belief in the intrinsic value of life.Gulliver himself, in their company, builds the sails of his skiff from "Yahoo skins".The Houyhnhnms' lack of passion surfaces during the scheduled visit of "a friend and his family" to the home of Gulliver's master "upon some affair of importance".