Abstract
There are two crucial problems for those who would take existence to be a ‘real’ property. (1) The predication of such a property of a thing appears insufficient to distinguish cases where the thing exists, on the one hand, from those where it does not exist on the other. That is, the property of existence does not add anythingto the concept of a thing. (2) If non-existent things are capable of having properties and identity – which is necessary to avoid an objection made by A. J. Ayer – then the identity of all things with all other things appears to follow. However, if the concept of existence is explained as a primitive property manifest as resistance toontological contradiction then these problems can be solved. The pay-off for considering existence to be a first-order predicate is, therefore, an argument against existing ontological contradictions.