
Thomas Pashby is Assistant Professor in the Department of Philosophy. He specializes in philosophy of physics with a particular interest in the interaction of physics, metaphysics, and the philosophy of science. He received his graduate training at the University of Pittsburgh, where he wrote his dissertation "Time and the Foundations of Quantum Mechanics" under the direction of John Earman and John D. Norton. He is currently engaged in research projects concerning the interpretation of quantum mechanics, the relational theory of time, and structural realism. What connects these projects is the idea that modern physics is best interpreted within an event ontology, which is to say that (metaphysically speaking) events and processes are fundamental rather than objects and properties.
He is also interested in the history of this idea, particularly its relationship to the relational logic and metaphysics of Bertrand Russell and A. N. Whitehead. His research in the philosophy of time concerns Aristotle's theory of time and the discrete continuum as well as the relationship between tense, modality and locality in relativistic spacetime. In the history of physics, he has a long-term project concerning Paul Dirac's discoveries in relativistic quantum theory and his use of projective geometry. He is a core faculty member of the Stevanovic Institute on the Formation of Knowledge and a board member of the PhilSci-Archive, a free preprint server for philosophy of science.
Selected Publications
“At What Time Does a Quantum Experiment Have a Result?” (2017) in Time in Physics (Eds. Renner & Stupar), Birkhauser: 141–160.
“How Do Things Persist? Location Relations in Physics and the Metaphysics of Persistence,” Dialetica 70, no. 3 (2016): 269–309
“Time and Quantum Theory: A History and a Prospectus,” Studies in History and Philosophy of Modern Physics 52 (2015): 24–38
“Reply to Fleming: Symmetries, Observables, and the Occurrence of Events,” Studies in History and Philosophy of Modern Physics 52 (2015): 44–47
“Taking Times Out: Tense Logic as a Theory of Time,” Studies in History and Philosophy of Modern Physics 50 (2015): 13–18.
“Do Quantum Objects Have Temporal Parts?” Philosophy of Science 80, no. 5 (2013): 1137–1147.
“Dirac’s Prediction of the Positron: A Case Study for the Current Realism Debate,” Perspectives on Science 20, no. 4 (2012): 440–75
Recent Courses
PHIL 21108/31108 Time After Physics
This course provides a historical survey of the philosophy of time. We begin with the problems of change, being and becoming as formulated in Ancient Greece by Parmenides and Zeno, and Aristotle’s attempted resolution in the Physics by providing the first formal theory of time. The course then follows theories of time through developments in physics and philosophy up to the present day. Along the way we will take in Descartes’ theory of continuous creation, Newton’s Absolute Time, Leibniz’s and Mach’s relational theories, Russell’s relational theory, Broad’s growing block, Whitehead’s epochal theory, McTaggart’s A, B and C theories, Prior’s tense logic, Belnap’s branching time, Einstein’s relativity theory and theories of quantum gravity. (B) (II)
PHIL 55792 Naturalized Metaphysics
This course examines the feasibility of doing metaphysics in a way that is responsive to, or determined by, the results of the natural sciences. In an influential book, Everything Must Go: Metaphysics Naturalized, published just over 15 years ago, philosophers of science James Ladyman and Don Ross advocated for a newly naturalized metaphysics and argued forcefully against alternative analytic approaches to metaphysics (in a chapter later described by Kyle Stanford as “embod[ying] the most admirable characteristics of a good slap across the face”). Unsurprisingly, many analytic metaphysicians responded defensively to this assault. Aside from providing the occasion for a good philosophical dispute, however, this debate resulted both in a literature full of fascinating methodological reflections on metaphysics, and a camp of metaphysicians who decided that being responsive to the results of science might not be a bad idea, leading to the creation of a (now thriving) Society for the Metaphysics of Science. As it happens, though, the outgoing President of the Society, Kerry McKenzie, has apparently become disillusioned with the project, arguing against the possibility of metaphysics tout court in a recent paper entitled “A Curse on Both Houses.” Against this argument we will place the detailed work of self-avowed naturalized metaphysicians, including David Wallace’s award-winning book The Emergent Multiverse. (III)
PHIL 22000/32000 Introduction to Philosophy of Science
We will begin by trying to explicate the manner in which science is a rational response to observational facts. This will involve a discussion of inductivism, Popper's deductivism, Lakatos and Kuhn. After this, we will briefly survey some other important topics in the philosophy of science, including underdetermination, theories of evidence, Bayesianism, the problem of induction, explanation, and laws of nature. (B) (II)
PHIL 38100 Whitehead’s Process and Reality
A close reading of Alfred North Whitehead's seminal work.
Undergraduates must petition to enroll.
PHIL 22003 Einstein for Everyone
Einstein’s revolutions in physics led to fundamental changes in how we understand the universe. Among other things, we seem to have learned from Einstein about the existence of black holes and gravitational waves, that time is not absolute but relative, that the universe is expanding, that gravity is not a force. But how is someone who doesn't know much physics to figure out if this or that moral really is vindicated by Einstein's work? This course covers just enough of Einstein's work at an elementary level to help answer such questions. High school math is required but we will provide an understanding of special and general relativity at a conceptual level, without calculations or problem sets. (B)
PHIL 22000/32000 Introduction to Philosophy of Science
We will begin by trying to explicate the manner in which science is a rational response to observational facts. This will involve a discussion of inductivism, Popper's deductivism, Lakatos and Kuhn. After this, we will briefly survey some other important topics in the philosophy of science, including underdetermination, theories of evidence, Bayesianism, the problem of induction, explanation, and laws of nature. (B) (II)
PHIL 22000/32000 Introduction to Philosophy of Science
We will begin by trying to explicate the manner in which science is a rational response to observational facts. This will involve a discussion of inductivism, Popper's deductivism, Lakatos and Kuhn. After this, we will briefly survey some other important topics in the philosophy of science, including underdetermination, theories of evidence, Bayesianism, the problem of induction, explanation, and laws of nature. (B) (II)
PHIL 22709/32709 Introduction to Philosophy of Quantum Mechanics
In this class we examine some of the conceptual problems associated with quantum mechanics. We will critically discuss some common interpretations of quantum mechanics, such as the Copenhagen interpretation, the many-worlds interpretation and Bohmian mechanics. We will also examine some implications of results in the foundations of quantum theory concerning non-locality, contextuality and realism. (B) (II)
Prior knowledge of quantum mechanics is not required since we begin with an introduction to the formalism. Only familiarity with high school geometry is presupposed but expect to be introduced to other mathematical tools as needed.
PHIL 53003 Explanation
This course surveys recent work on explanation across philosophical disciplines. Beginning with classic accounts of scientific explanation we will proceed to consider recent work on mechanical explanation, mathematical explanation, causal explanation (particularly in the physical and social sciences), the relation between explanation and understanding, and metaphysical explanation (particularly the idea of explanation as ground). (II)
PHIL 22000 Introduction to Philosophy of Science
We will begin by trying to explicate the manner in which science is a rational response to observational facts. This will involve a discussion of inductivism, Popper's deductivism, Lakatos and Kuhn. After this, we will briefly survey some other important topics in the philosophy of science, including underdetermination, theories of evidence, Bayesianism, the problem of induction, explanation, and laws of nature. (B)
PHIL 21108/31108 Time After Physics
This course provides a historical survey of the philosophy of time. We begin with the problems of change, being and becoming as formulated in Ancient Greece by Parmenides and Zeno, and Aristotle’s attempted resolution in the Physics by providing the first formal theory of time. The course then follows theories of time through developments in physics and philosophy up to the present day. Along the way we will take in Descartes’ theory of continuous creation, Newton’s Absolute Time, Leibniz’s and Mach’s relational theories, Russell’s relational theory, Broad’s growing block, Whitehead’s epochal theory, McTaggart’s A, B and C theories, Prior’s tense logic, Belnap’s branching time, Einstein’s relativity theory and theories of quantum gravity. (B) (II)
PHIL 22709/32709 Introduction to Philosophy of Quantum Mechanics
In this class we examine some of the conceptual problems associated with quantum mechanics. We will critically discuss some common interpretations of quantum mechanics, such as the Copenhagen interpretation, the many-worlds interpretation and Bohmian mechanics. We will also examine some implications of results in the foundations of quantum theory concerning non-locality, contextuality and realism. (B)
Prior knowledge of quantum mechanics is not required since we begin with an introduction to the formalism. Only familiarity with high school geometry is presupposed but expect to be introduced to other mathematical tools as needed.
PHIL 55100 The Development of Whitehead's Philosophy of Nature
In this course we will read Whitehead with the aim of understanding how he arrived at his mature views, i.e., the "philosophy of organism" expressed in Process and Reality (1929). The development of Whitehead's philosophy can be traced back to a planned fourth volume of Principia Mathematica (never completed) on space and time. This course will examine how these concerns with natural philosophy led Whitehead to develop his philosophy of organism. Beginning in the late 1910s, we will read over 10 years of published work by Whitehead, supplemented by recently discovered notes from his Harvard seminars 1924/25 and selected commentaries. (II)
PHIL 58108 The Philosophy of Howard Stein
Howard Stein's impressive body of work is notable for its tight integration of history of science with philosophy of science. Topics include: theories of spacetime structure (Newtonian and relativistic), the conceptual structure of quantum mechanics, the methodology of science in general and the character of scientific knowledge, and the history of physics and mathematics. Readings by Stein will be supplemented by primary historical texts and secondary philosophical literature, including selections from a forthcoming edited collection on Stein. (II)
PHIL 20100/30000 Elementary Logic
An introduction to the techniques of modern logic. These include the representation of arguments in symbolic notation, and the systematic manipulation of these representations in order to show the validity of arguments. Regular homework assignments, in class test, and final examination.
PHIL 22000/32000 Introduction to the Philosophy of Science
We will begin by trying to explicate the manner in which science is a rational response to observational facts. This will involve a discussion of inductivism, Popper's deductivism, Lakatos and Kuhn. After this, we will briefly survey some other important topics in the philosophy of science, including underdetermination, theories of evidence, Bayesianism, the problem of induction, explanation, and laws of nature. (B) (II)
PHIL 22000/32000 Introduction to the Philosophy of Science
We will begin by trying to explicate the manner in which science is a rational response to observational facts. This will involve a discussion of inductivism, Popper's deductivism, Lakatos and Kuhn. After this, we will briefly survey some other important topics in the philosophy of science, including underdetermination, theories of evidence, Bayesianism, the problem of induction, explanation, and laws of nature. (B) (II)
PHIL 22709 Introduction to Quantum Mechanics
In this class we examine some of the conceptual problems associated with quantum mechanics. We will critically discuss some common interpretations of quantum mechanics, such as the Copenhagen interpretation, the many-worlds interpretation and Bohmian mechanics. We will also examine some implications of results in the foundations of quantum theory concerning non-locality, contextuality and realism. Prior knowledge of quantum mechanics is not required since we begin with an introduction to the formalism, but familiarity with matrices, freshman calculus and high school geometry will be presupposed.
PHIL 54410 Russell's Philosophy of Science in Context
We will read work from Russell's entire career with a particular focus on both his philosophy of science and the role of science (including geometry and mathematics) in his philosophical development. We will also look at his influences and contemporaries (including Whitehead, Keynes and Carnap) and at how Russell's views on causation and structuralism have been treated by more recent philosophers of science. (II)