'identity' includes a family of relations and is wrongly restricted to what satisfies leibniz's law: diachronic and strict identity are related since the criteria of the former are just the criteria of continuity of stages of the strictly identical continuant. A general account can be given in terms of the preservation of a weighted preponderance of properties of the stages. Puzzle cases arise because of contextual shifts in the weightings assigned; in the case of persons this is particularly clear because (...) of change of emphasis between mental and physical, Both of which classes of predicate are applicable. (shrink)