Round square copula
The "Round square copula" is a common example of the Dual Copula Strategy used in reference to the problem of nonexistent objects as well as their relation to problems in modern philosophy of language. The issue arose, most notably, between the theories of Alexius Meinong, Bertrand Russell - Gilbert Ryle playing a minor part as well in the eventual dismissal of Meinong's object theory (see Meinong's 1904 book, Theory of Objects).
The strategy employed is the Dual Copula Strategy, which is used to make a distinction between relations of properties and individuals. It entails creating a sentence that isn't supposed to make sense by forcing the term "is" into ambiguous meaning.
By borrowing Edward Zalta's notational method (Fb stands for b exemplifies the property of being F; bF stands for b encodes the property of being F), and using a revised version of Meinongian object theory which makes use of a dual copula distinction (MOTdc), we can say that the object called "the round square" encodes the property of being round, the property of being square, all properties implied by these, and no others. But it is true that there are also infinitely many properties being exemplified by an object called the round square (and, really, any object) - e.g. the property of not being a computer, and the property of not being a pyramid. Note that this strategy has forced "is" to abandon its predicative use, and now functions abstractly.
When one now analyzes the round square copula using the MOTdc, one will find that it now avoids the three common paradoxes: (1) The violation of the law of contradiction, (2) The paradox of claiming the property of existence without actually existing, and (3) producing counterintuitive consequences. Firstly, the MOTdc shows that the round square does not exemplify the property of being round, but the property of being round and square. Thus, there is no subsequent contradiction. Secondly, it avoids the conflict of existence/non-existence by claiming non-physical existence: by the MOTdc, it can only be said that the round square simply does not exemplify the property of occupying a region in space. Finally, the MOTdc avoids counterintuitive consequences (like a 'thing' having the property of nonexistence) by stressing that the round square copula can be said merely to encode the property of being round and square, not actually exemplifying it. Thus, logically, it does not belong to any set or class.
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