Commensurability in economics arises whenever there is a common measure through which the value of two entities can be compared. Commensurability has two versions: * Strong commensurability arises when it is possible to give cardinal values to entities as a consequence of utilising a given property to measure entities. Thus we can say "This is two and a half times more valuable than that." This implies value monism. * Weak commensurability arises when it is only possible to apply ordinal values to entities as a consequence of utilising a given property to rank entities, i.e., it is sufficient to say "This is more valuable than that." This is consistent with value-pluralism.