Abstract Objects: An Introduction to Axiomatic Metaphysics (1983) is the title of a publication by Edward Zalta that outlines abstract object theory.
AOT is a
dual predication approach (also known as "dual copula strategy") to abstract objects[3][4] influenced by the contributions of
Alexius Meinong[5][6] and his student
Ernst Mally.[7][6] On Zalta's account, there are two modes of
predication: some objects (the ordinary
concrete ones around us, like tables and chairs) exemplify properties, while others (abstract objects like numbers, and what others would call "
nonexistent objects", like the
round square and the mountain made entirely of gold) merely encode them.[8] While the objects that exemplify properties are discovered through traditional empirical means, a simple set of axioms allows us to know about objects that encode properties.[9] For every set of properties, there is exactly one object that encodes exactly that set of properties and no others.[10] This allows for a
formalizedontology.
In 2007, Zalta and
Branden Fitelson introduced the term computational metaphysics to describe the implementation and investigation of formal, axiomatic metaphysics in an
automated reasoning environment.[18][19]
^Zalta, Edward N. (2004).
"The Theory of Abstract Objects". The Metaphysics Research Lab, Center for the Study of Language and Information, Stanford University. Retrieved July 18, 2020.
^Ernst Mally (1912), Gegenstandstheoretische Grundlagen der Logik und Logistik (Object-theoretic Foundations for Logics and Logistics), Leipzig: Barth,
§§33 and 39.
^Zalta (2024:240): "Some non-core λ-expressions, such as those leading to the Clark/Boolos, McMichael/Boolos, and Kirchner paradoxes, will be provably empty."
^Jesse Alama, Paul E. Oppenheimer,
Edward N. Zalta,
"Automating Leibniz's Theory of Concepts", in A. Felty and A. Middeldorp (eds.), Automated Deduction – CADE 25: Proceedings of the 25th International Conference on Automated Deduction (Lecture Notes in Artificial Intelligence: Volume 9195), Berlin: Springer, 2015, pp. 73–97.
Edward N. Zalta,
"Typed Object Theory", in José L. Falguera and Concha Martínez-Vidal (eds.), Abstract Objects: For and Against, Springer (Synthese Library), 2020.