Abstract
Many philosophers have attempted to offer a logical theory of objects, employing different techniques. Thus R. Carnap tried to “reconstruct” logically the world by using the modern symbolic logic, while N. Goodman “constructed” the world with the help of the calculus of individuals or the logic of part-whole relations. W.V. Quine helped to steer the attention toward the question of ontological commitment and toward a theory of objects produced by a logical analysis of natural languages. Recently, there have been controversial discussions concerning the metaphysical and logical aspects of objects in actual and possible worlds as well as new contributions to the theory of nonexistent objects, rekindling the old Russell-Meinong controversy. It seems that even the proposed theories of events, such as that of R. M. Martin, maintain the great significance of the notion of an object. Then there is a plethora of the so-called intensional objects, such as the alleged objects of propositional attitudes, the story of which is tied with the names of Frege, Russell, Carnap and many others. Is it possible to give an all-embracing theory of objects which would satisfy all the parties involved? Although such possibility may be very questionable, the instrumental role of logic for the development of the metaphysical theories of objects is indisputable. Two factors are, however, involved in the constitution of a logical theory of objects: the basis or the given data from which the theory starts; the logical apparatus employed, i.e., the logical axioms and rules of inference, just as the relevant semantical rules which are formulated in the metalanguage. While the logical apparatus is usually very clear, at least in the case of the formally well-construed theories, the given basis of a metaphysical theory T—as we may call it—might contain many tacit assumptions which would need a lot of clarification. It seems that philosophers fight more about the presuppositions and assertions of their systems than about the logic involved. I would like to discuss the interplay between the above two factors, starting with the realm of the given objects. As to the second factor—the logical apparatus involved—the contributions of first-order predicate logic and of the calculus of individuals will be considered.