An effort is made to show that every conservation problem assesses 2 forms of conservation-identity and equivalence-and that Piaget's theory of conservation is a theory of the conservation of identity and not of equivalence. Misunderstandings of Piaget's position on conservation are attributed to his failure to make clear the distinction between the 2 forms of conservation, and his tendency to interpret conservation problems as assessments of the conservation of identity when, in fact, equivalence is the only form of conservation directly assessed by the standard conservation task.