Overview

I present the fifth volume of the series titled Introduction to Thomistic Metaphysics. In this work, I delve into the concept of entities in motion, with its explanation grounded in the doctrine of act and potency. While some consider the development of this doctrine to be the "essence" of Thomism, I limit myself to acknowledging this viewpoint without fully endorsing it. I find the matter to be less clear-cut at the moment. What is certain, however, is that, following Aristotle and St. Thomas, the problem of being and existence cannot be studied without referring to the concepts of act and potency. Being is spoken of in various senses, and one of them is being in act and being in potency. Delving into this inevitably leads us to the realm of motion, change, and the becoming of being. This, in turn, takes us into the Philosophy of Nature or Physics. Although it may seem audacious to separate the Philosophy of Being from the Philosophy of Nature in Aristotle, we have respected this division. The metaphysical contemplation of change or motion necessitates its physical consideration. I have endeavored to provide as much clarity and didactic explanation as possible on a subject where Aristotle was not as clear and didactic as one might wish. His interchangeable use of the terms "change" and "motion," initially considering them distinct and then synonymous, can be confusing. I have omitted a Prologue, deeming it superfluous, and instead, I proceed directly to the topics, organized into nine chapters as follows: 1. Philosophy of Nature. 2. The Reality of Change. 3. Change. 4. The Movement. 5. The Matter. 6. The Form. 7. Introduction to Act and Potency. 8. The Potency. 9. The Act. Finally, an Epilogue presented in the form of questions and answers and a section for Notes. As is my custom, there are numerous references to other authors.