Introduction to Metaphysics

Working from a realist Thomistic epistemology, Ashley asserts that we must begin our search for wisdom in the natural sciences; only then, he believes, can we ensure that our claims about immaterial and invisible things are rooted in reliable experience of the material.

This is the first comprehensive textbook on higher-order logic that is written specifically to introduce the subject matter to graduate students in philosophy. The book covers both the formal aspects of higher-order languages―their model theory and proof theory, the theory of λ-abstraction and its generalizations―and their philosophical applications, especially to the topics of modality and propositional granularity. The book has a strong focus on non-extensional higher-order logics, making it more appropriate for foundational metaphysics than other introductions to the subject from computer science, mathematics, and linguistics.