Solutions to Puzzles of Existential Generalisation



Year of publication 2022
Type Appeared in Conference without Proceedings
MU Faculty or unit

Faculty of Arts

Description The present paper addresses several puzzles related to the Rule of Existential Generalization, (EG). In solution to these puzzles, I clearly distinguish (EG) from a modified Rule of Existential Quantifier Introduction, which is derivable from (EG). Both these rules are often confused and both are considered as primitive. But I show that (EG) itself is derivable from the proper Rule of Existential Quantifier Introduction. The latter rule must be primitive in logical systems that treat both total and partial functions, for the universal and the existential quantifiers are not interdefinable in them. An appropriate natural deduction for such a system is deployed. It utilises an adequate definition of substitution which is capable of handling not only a higher-order quantification, but also (hyper)intensional contexts.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.