The historical development towards the current standard account of I as a ‘pure indexical’ (‘purism’) has two main features. First, the gradual acquisition of a logical apparatus which can distinguish genuine from non-singular referring expressions, and categorize the latter into names, descriptive terms, indexicals, and so on. Second, the development and acceptance of three supposed doctrines: that a simple rule is sufficient to give the meaning of I (‘rule theory’); that one can use I to express thoughts without having to identify what is being referred to (‘independence’); and that as a matter of the meaning of I, any use of the term is logically guaranteed against failure to refer (‘the guarantee’).
Keywords: indexicals, logical apparatus, singular referring expression, names, descriptive terms, rule theory, independence, the guarantee, Descartes, Kant