 Frankfurt points out that this is inadequate as a definition of personhood since “there are many entities beside persons that have both mental and physical properties” (Frankfurt 1971: 5). It may be, however, that Strawson’s formulation here is somewhat loose, and that his central idea is that persons are those entities that self­-ascribe both types of predicate, a condition that perhaps rules out at least most non-human animals. After all chapter 3 of Individuals, entitled “Persons”, is primarily concerned with the conditions of such self-ascription, with “the use we make of the word ‘I’” (P.F. Strawson 1959: 94).