Zachary William Lee Goodsell

I am a philosophy PhD candidate at the University of Southern California. I started in Fall 2018. Before that, I completed a Bachelor of Science in mathematics at the University of Queensland (2014-2016) and a Bachelor of Arts (Honours) in philosophy at the University of Sydney (2017).

My research interests include logic, decision theory, epistemology and the philosophy of probability, ethics, metaphysics, the philosophy of mathematics, and the philosophy of language.

Contact me at zgoodsel[at]usc[dot]edu. [CV]

Publications

2022

“Tossing Morgenbesser's Coin”. In Analysis 82 (2): 214-221. Morgenbesser's Coin is a thought experiment that exemplifies a pervasive tendency to infer counterfactual independence from causal independence. I argue that this tendency is mistaken by way of a closely related thought experiment.

“Arithmetic is Determinate”. In the Journal of Philosophical Logic 51: 127-150. Arithmetical truths are shown to be determinately true in a minimal plural modal logic for determinacy.

2021

“A St Petersburg Paradox for Risky Welfare Aggregation”. In Analysis 81 (3): 420-426. The principle of Anteriority says that prospects are equally good if they are equally good for every possible person. I show that Anteriority is inconsistent with some very plausible principles of axiology and decision theory.

2020

“What is an Extended Simple Region?” (with Michael Duncan and Kristie Miller). In Philosophy and Phenomenological Research 101 (3): 649-659. We propose a novel view about what could make a spatial region extended (that is, bigger than a point), and investigate some consequences of this view.

Works in progress

(* denotes draft available. Send me an email.)

Philosophy of logic and mathematics

*Logical Foundations with Juhani Yli-Vakkuri. In this book we put forward a new logical system, LF, and demonstrate how to reduce logic and mathematics to LF, as well as semantics to LF plus the axioms of syntax.

“Mathematical Contingency”. It is usually assumed that mathematics and logic are non-contingent domains. I show how, given various background logics, the non-contingency of various aspects of mathematics and logic can be proved.

Philosophy of language

“Defining Meaning” with Juhani Yli-Vakkuri. We show how to define meaning in finite-order fragments of the simply typed lambda calculus, and investigate the philosophical upshot of this method.

Epistemology and Philosophy of Probability

*“An argument for probabilistic regularity”. The principle regularity says that possibilities are strictly more likely than impossibilities. Regularity is almost universally rejected in contemporary treatments of probability. I argue for regularity from decision-theoretic premisses.

Axiology and decision theory

*[Name anonymised for review.] A general axiomatic framework for decision theory in the presence of unbounded value is developed by investigating various consequences and consistency results.

*“Adding Lotteries”. Seidenfeld, Schervish, and Kadane (2009) have proposed a principle which says that to compare two risky prospects, you can look at the how much utility you would miss out on by taking one over the other. As they recognise, this principle has important ramifications for the rest of decision theory. I further develop the arguments for and against the principle.

“Symmetries of Value”. Various authors have argued that multiplying the utility of all the possible outcomes by the same amount in each of two prospects should not change which of the two is better. I derive some surprising consequences of principles like this, show that they are nevertheless consistent, and argue that we should accept them.

My dissertation is also on decision theory. It consists of the above three papers, as well as a chapter on the application population ethics, and on decision theory under unorthodox probabilistic assumptions.

Ethics

*“Morality does not encroach” with John Hawthorne. The thesis of moral encroachment says that morality can affect what doxastic states are epistemically appropriate. John and I argue that the arguments and motivations for accepting moral encroachment would also show that morality affects which credences are most epistemically appropriate. We then show that widely accepted constraints on credence do not leave room for moral encroachment as its proponents envision.

Notes and works not in progress

These are things that I do not intend to publish, but would like to discuss.

1. A note on adding a novel axiom to the logic of Andrew Bacon and Cian Dorr's “Classicism”.

2. A note proving a generalization of the main result of “Symmetries of Value”.

3. A paper about what you know about a sequence of coin tosses before it happens.

4. An old draft of “Mathematical Contingency” that also gave rise to “Arithmetic is Determinate”.

Website last updated September 2022.