  As a pragmatist, Ramsey individuates beliefs by attending to their causes and effects. Thus, attitudes towards two sentences prompted by the same causes and producing the same effects express the same belief, no matter the linguistic constitution of the sentences used to express it. ‘Belief’, Ramsey acknowledges, is an ambiguous term (1927a, [PP] 40). Both human beings and non-linguistic animals can be said to possess beliefs. In non-linguistic animals, beliefs are dispositions to act; in linguistic animals, beliefs are mental states with a particular kind of content that involves entertaining words. Chickens that avoid eating a particular kind of caterpillar, due to systematically connecting it with disagreeable past experiences, believe that caterpillars of this kind are poisonous. This is Ramsey’s causal theory of belief, which Dokic and Engel (2002, 24) extend to beliefs of any kind and attribute to Peirce’s influence on Ramsey. The beliefs of linguistic animals are specifically defined in terms of attitudes towards complexes of signs with logical structure (Hookway 2005,  185). Both kinds of belief, linguistic and non-linguistic, are analysed in pragmatist terms, in which ‘the relations between belief and action do take centre stage in some of [Ramsey’s] most influential writings on this topic’ (Hookway 2005, 186).