  Meinong (1904) supposed that objects like Zeus, the fountain of youth, Sherlock Holmes, etc., are non-existent objects which exemplify the properties attributed to them. On his view, the fountain of youth is an object that instantiates both the property of being a fountain and that of having waters which confer everlasting life. But it fails to instantiate the property of existence. Meinong seemed to suppose that for any group of properties, there is an object which instantiates those properties. Some of the resulting objects exist and others do not.  Russell (1905) found this view of intentional objects ontologically unacceptable since it involves the acceptance of entities such as golden mountains (which are inconsistent with physical and chemical laws) and round squares (which are inconsistent with the laws of geometry). His theory of definite descriptions was precisely designed to avoid these ontological consequences (see section 5). However, by clarifying distinctions proposed by both Meinong and his student Ernst Mally, Parsons (1980) has recently offered a theory of non-existent objects, which is based on the assumption that existence is a special kind of property. This theory uses a quantifier “∃”, which does not imply existence. To assert existence, he uses the predicate “E!”. Thus, the assertion that there are non-existent objects can be represented in Parsons’ theory without contradiction by the logical formula “∃x(~E!x).” Furthermore, Parsons distinguishes between “nuclear” and “extranuclear” properties. Only the former, which are ordinary, non-intentional kinds of properties, contribute to individuating objects. The set of extranuclear properties involve intentional properties, modal properties and existence. Armed with this distinction among properties, Parsons (1980) has been able to avoid Russell’s objections to Meinong’s naive theory of intentional objects. (For further details, see Parsons, 1980.) An original account of the possibility of entertaining true thoughts about non-existent objects, based on the contrast between pleonastic (or representation-dependent) and non-pleonastic (natural or substantial) properties, has been developed by Crane (2013). 