For his third book, Philosophy Professor André Gallois provided a new twist on philosophical problems dating back to ancient civilization. Gallois recently answered questions about his work, which is titled "The Metaphysics of Identity."

Q. What is the book about, from a layperson's perspective?

A. The book is about persistence and change. We confront some deeply puzzling problems when we consider how objects manage to exist at different times while undergoing change: in particular gaining or losing parts. Here is an example of such a problem. Suppose you have a car that has been around for a long time. Early in its career, a new battery replaced the original one. Sometime later new windscreen wipers were installed. So it goes until all of the original parts are replaced. Is it still the same car?

Q. As the title suggests, (new problems) how might this be possible when we are talking about concepts that are centuries old? Or, is this a common tenet of philosophers, insofar as philosophy is always evolving?

A. "New Problems" is a bit of a misnomer. Most of the problems I discuss go back to the ancient Greeks. "New Solutions" might be better. Still, one can pose new problems using old concepts.

Q. Who might pick up your new work? Students? People with a general desire/knowledge of metaphysics?

A. The book is primarily intended for advanced students. Undergraduates in their final year and postgraduates still engaged in coursework.

Q. Is writing a book containing deep subject material more labor, or a labor of love?

A. Yes, it is really a labor: I probably would not have done it unless invited.