Abstract

The paper deals with the problem whether there can exist indeterminate identity. If one accepts Evans’s argument, then statements about indeterminate identity can be true, but only those, in which at least one of the singular terms does not refer determinately. One does not have to explain all vagueness as semantic, i.e. as indeterminacy of meaning, because some such statements can be true on account of indeterminacy of reality. This can be shown in the particular quantum case introduced by Lowe concerning the identity of an absorbed and emitted electron. The singular terms within the identity statements in this example are to be understood in the way pointed out by Abasnezhad and in the manner Barnes and Williams take names in statements of identity between Kilimanjaro and one of the precise aggregates of particles of which the mountain consists: One of the names refers indeterminately. This indeterminacy is of the kind belonging to indefinite descriptions. The issue of individuality on quantum level can be understood using resources of structural realism of James Ladyman.