The chapter analyses the debates on the relation between self-interest and sociability in eighteenth-century British moral philosophy. It focuses on the selfish hypothesis, i.e. on the egoistic theory that we are only motivated by self-interest or self-love, and that our sociability is not based on disinterested affections, such as benevolence. The selfish hypothesis is much debated especially in the early eighteenth century (Mandeville, Shaftesbury, Hutcheson, Butler, Clarke, Campbell, Gay), and then rather tacitly accepted (Hartley, Tucker, Paley) or rejected (Hume, Smith, (...) Reid). It is asserted for example by philosophers with an Augustinian and Epicurean background and by the associationists, yet rejected especially by thinkers inspired by Stoic ideas. In particular for these latter authors, who emphasise the disinterested aspects of moral motivation, the debates on the selfish hypothesis have an important moral dimension. Others again argue that specific kinds of self-interest motivate virtuous actions. (shrink)