Achille Varzi is the John Dewey Professor of Philosophy at Columbia University and Bruno Kessler Honorary Professor at the University of Trento. He is a renowned metaphysicist and logician, and widely regarded as the world’s leading mereologist. Achille—or Varzi, as he is affectionately known around the halls of Columbia’s philosophy department—is also an immensely important philosophical figure for Robinson, and a prior denizen of this podcast multiverse (see episode 47 for Achille’s introduction to metaphysics and nominalism). In this installment, however, Robinson and Varzi delve deep into the history, logic, and metaphysics of mereology, the theory of parts and the parthood relation. For a more in-depth and rigorous discussion of the material covered in this episode (because yes, this is in fact possible!), check out Achille and A.J. Cotnoir’s fantastic monograph on the subject, linked below:

Mereology (Oxford, 2021): https://a.co/d/gFKrO3U

Mereology (SEP): https://plato.stanford.edu/entries/mereology/

Achille’s Website: http://www.columbia.edu/~av72/

Correction: Achille mistakenly refers to Verity Harte, author of Plato on Parts and Wholes, as Valery Harte. 

OUTLINE

00:00 In This Episode…

1:02 Introduction

4:44 Achille’s Start in Mereology

8:19 The Etymology of Mereology

18:00 What is Mereology?

20:03 Ancient Mereology

30:04 Medieval Mereology and the Liar Paradox

47:33 Husserl’s Formal Ontology

1:10:28 Leśniewski and the Formalization of Mereology

1:21:25 Whitehead, Leonard & Goodman, and the History of Mereology

1:34:26 The Language of Mereology

1:39:44 Mereology and the Axiomatic Method

1:47:46 More on the Language of Mereology

1:52:37 The Mereological Formalism

2:16:42 Composition

2:29:35 Misconceptions about Mereological Fusion 

3:01:10 Gunk, Junk, and Hunk

3:10:15 Applications of Mereology

3:15:50 Mereological Pluralism

3:31:43 Mereotopology and the Ordering Axioms 

Robinson’s Website: http://robinsonerhardt.com

Robinson Erhardt researches symbolic logic and the foundations of mathematics at Stanford University. Join him in conversations with philosophers, scientists, weightlifters, artists, and everyone in-between.