Alexander R. Pruss

We show that there is a version of dualism—and even of substance dualism—on which (a) the physical is causally closed, (b) there is no systemic overdetermination, (c) mental states are not physical states, and yet (d) mental states have physical effects. This shows that commonly-made claims about dualism about causal closure are not quite correct. The theory offered can be seen as a version of Aquinas’s theory of sensory consciousness, where sensory consciousness is partly constituted by the soul’s informing of the body and partly by the states of physical organs.

Privative evils are evils that deprive someone of a due good. Chapter 1 considers a special but widespread type of a privative evil, namely impairment. It argues that even though an impairment may deprive someone of a significant and due good, impairments as such do not make for a significant case against theism. The argument is based on thought experiments suggesting that it does not make one significantly worse off when one is lacking a _due_ good as opposed to when one is merely lacking a good, even when the good is itself significant. It is suggested that the point generalizes beyond impairment to at least some other forms of privative evils. And if St. Augustine is right that all evils are privative, then this could form a significant component of a general theodicy.

Plural quantification, often used to evade Russell paradoxes, will lead back to them, given certain assumptions about propositions. This chapter provides a more generalized version of the path to paradox by showing that any theory that makes possible the construction of an appropriate packaging relation falls prey to a Russell paradox. It gives examples of widely-held metaphysical theories that require such a relation. It shows that the paradoxes that can result from plural quantification are more widely damaging, and harder to tame, than has been recognized. It also displays formal requirements that any metaphysical framework with a packaging relation must meet if it is to have a chance of escaping self-contradiction. The chapter first gives the general paradox-generating setup, and then shows how three families of metaphysical assumptions allow one to instantiate it. It concludes by assessing the aftermath of the arguments presented.

Any scientific theory that applies to sufficiently many cases is likely to have an anomaly: a case that appears to be a counterexample. An anti-sceptical account is given of why this fact does not refute most scientific theories, or even render them significantly less plausible, and it is discussed how bona fide refutation of a scientific theory is to be distinguished from mere anomaly mongering, like that involved in much creationist and Intelligent Design arguing. A spectrum of responses a scientist can make to an anomaly is enumerated. It is then shown that standard Rowe-style inductive arguments from evil as they stand are mere anomaly mongering, and hence do not by themselves significantly lower the plausibility of theism, and analogues of the spectrum of responses a scientist can make to an anomaly are discussed.

The No Inferior Choice (NIC) principle says that if God is choosing between options A and B where A is better than B, God does not choose B since he has a conclusive reason to choose A over B. When conjoined with Rowe’s claim that for any world w that God can actualize God could do better than actualizing w, NIC yields the conclusion that God doesn’t actualize any world, and hence that God doesn’t exist. Yet, if NIC is conjoined with the claim that there is a best world for God to actualize, then it yields the unwelcome conclusion that there is only one world God can actualize, which severely limits God’s free will. This chapter argues that there is massive incommensurability between possible worlds, enough to undercut our confidence in Rowe’s claim that for every world there is a better and allow for a wide variety of worlds that God can create.

Functionalism in the theory of mind requires an account of function that has a normative component—mere conditional connection (whether indicative or sub-junctive) is not enough. For instance, a component of a computing system isn’t an adder just in case its output is always or would always be the sum of the inputs, since any computing system in a world with as much indeterminism as ours can err or malfunction. Two general reductions of normative language have been proposed that one might wish to apply to the problem of defining proper function: the evolutionary reduction (Wright, Millikan) and the agential reduction (Plantinga). We argue that whatever the merits of the reductions in other contexts, a functionalist theory of mind that defines proper function in either of these ways must fail. The argument proceeds by first showing the agential reduction is viciously circular in the context of a functionalist theory of agency. Second, if functionalism about mind is true and proper function is reducible evolutionarily, then it is possible to have a situation in which the presence or absence of mental properties depends in an implausibly spooky, acausal way on remote facts. It is plausible that the only currently avail-able way for the functionalist to meet these challenges is to accept irreducible end-directed causal powers of minds and/or their functional parts, in accordance with a broadly Aristotelian tradition.

It is well-known that one cannot use first-order logic with identity and the predicates $$\operatorname{Cat}(x)$$ and $$\operatorname{Dog}(x)$$ to say that there are more cats than dogs. Nonetheless, Goodman and Quine (J Sym Log 12:105–122, 1947) offered an ingenious translation of the sentence into a richer but thoroughly finitist and nominalist language with mereological vocabulary and size comparison for individuals. However, their translation as it stands fails in the case of counting comparisons involving overlapping objects (say, conjoined twin cats). Furthermore, we prove that no general translation of equinumerosity (and hence of “more”) can be given in the overlapping object setting using the predicates in Goodman and Quine’s translation, assuming size comparison can be cashed out by counting mereological atoms, and we use computational complexity theory to prove a more general inexpressibility result. We end with some open questions.

Many have the intuition that human persons are both extremely and equally valuable. This seeming extremity and equality of vale is puzzling: if overall value is the sum of one’s final value and instrumental value, how could it be that persons share the same extreme value? One way that we can solve the Value Puzzle is by following Andrew Bailey and Josh Rasmussen. Philosophy and Phenomenological Research, 103, 264–277 (2020) and accepting that persons have infinite final value. But there are some significant downsides to their way of thinking about values, which relies on the extended real numbers. We offer a different approach: if we model values using the hyperreal numbers, we can capture many of our intuitions about the extremity and relative equality of human value without incurring the substantial theoretical costs of using the extended real numbers. We also examine other ways of modeling the infinite value of persons and evaluate the strengths and weaknesses of these other accounts compared to ours.

Since Aristotle, teleological directedness has generally been taken to be a directedness at a goal the possession of which fulfills the teleology. I will argue that this is an oversimplification of agential and non-agential teleologies. My main argument is based on reflection on a common phenomenon in sports and games where we inaccurately describe ourselves as having an end and use the phrase “as F as possible,” where F is a term like “fast,” “far,” “high a score,” etc., in our description of that end. Such cases also come up in much more important pursuits such as that of knowledge, as well as in non-agential cases. I then offer a generalization of the goal-based analysis which better handles these cases and briefly discuss applications to ethics and eschatology. I end by offering a solution to the famous problem of the relationship between the natural and supernatural ends in Aquinas.

There are four well-known models of fundamental objective probabilistic reality: classical probability, comparative probability, non-Archimedean probability, and primitive conditional probability. I offer two desiderata for an account of fundamental objective probability, comprehensiveness and non-superfluity. It is plausible that classical probabilities lack comprehensiveness by not capturing some intuitively correct probability comparisons, such as that it is less likely that 0=1 than that a dart randomly thrown at a target will hit the exact center, even though both classically have probability zero. We thus want a comparison between probabilities with a higher resolution than we get from classical probabilities. Comparative and non-Archimedean probabilities have a hope of providing such a comparison, but for known reasons do not appear to satisfy our desiderata. The last approach to this problem is to employ primitive conditional probabilities, such as Popper functions, and then argue that $$P(0=1\mid 0=1\text{ or hit center})=0<1=P(\text{hit center} \mid 0=1\text{ or hit center})$$. But now we have a technical question: How can we reconstruct a probability comparison, ideally satisfying the standard axioms of comparative probability, from a primitive conditional probability? I will prove that, given some plausible assumptions, it is impossible to perform this task: conditional probabilities just do not carry enough information to define a satisfactory comparative probability. The result is that of the models, no one satisfies our two desiderata. We end by briefly considering three paths forward.

The privation theory of evil was developed by St. Augustine largely as a response to the Metaphysical Problem of Evil: If all things that exist are God or come from God, how can there be evil? I begin by noting that the simple theory that all evil is a privation is subject to decisive counterexamples, and that a refined theory due to Avicenna and Aquinas requires an implausible “Goldilocks ontology”: bloated by including certain odd items like tokens of truth or authorization, but not so bloated as to include privations. Instead, I shall argue that we can drop the privation theory of evil and still answer the Metaphysical Problem of Evil in the same spirit, by denying that evils really exist, albeit without insisting that they are privations. The result puts much less pressure on one’s ontology.

John Post criticized Richard Gale’s work for neglecting to consider Patrick Grim style arguments against quantification over all propositions. Such arguments would throw into question the possibility of an omniscient being and destroy the Weak Principle of Sufficient reason that Gale and I have defended, the principle that each true or at least contingently true proposition is possibly explained. Post mounts a Grim-style argument against quantification over all propositions. However, I show that, despite assurances to the contrary, Post’s argument depends on the assumption that if one can quantify over all propositions, then there is a set-like collection of all propositions. I show this by demonstrating that Post’s argument implicitly uses the Schroeder-Bernstein theorem from set theory. On the other hand, a linguistic version of Post’s argument, while not directly relevant to the theological cases, gives rise to an independently interesting paradox resembling Berry’s.

I shall discuss the problem of the definition of lying and the formulation of the duty of truthtelling. I shall argue that the morality of assertion is a special case of the morality of endorsement, and that a criterion of adequacy for an account of lying is that it handles certain cases of dishonest endorsement as well. Standardviews of lying fail to do so. I shall offer an account of the duty of honest endorsement in terms of the intention to avoid falsehood. But, in the end, we may simplyhave reason to go back to the naïve view that lying is saying falsehoods.

I explore the connections between presentist and non-presentist theories of time and the doctrine of divine conservation. Presentism naturally leads to the idea that causation must be simultaneous, which makes diachronic causal chains problematic. Divine conservation, however, allows one to extend simultaneous causation into diachronic chains, but at the expense of introducing a certain measure of occasionalism. This occasionalism can be removed at the expense of making all diachronic causal series indeterministic. On the other hand, a non-presentist (eternalist or growing block) theory of time allows for a very different concurrentist theory of divine conservation. This theory appears somewhat superior to the presentist one, which gives the classical theist some reason to prefer non-presentism.

Eugene Mills has recently argued that human organisms cannot begin to exist at fertilization because the evidence suggests that egg cells persist through fertilization and simply turn into zygotes. He offers two main arguments for this conclusion: that ‘fertilized egg’ commits no conceptual fallacy, and that on the face of it, it looks as though egg cells survive fertilization when the process is watched through a microscope. We refute these arguments and offer several reasons of our own to think that egg cells do not survive fertilization, appealing to various forms of essentialism regarding persons, fission cases, and a detailed discussion of the biological facts relevant to fertilization and genetics. We conclude that it is plausible, therefore, that human organisms begin to exist at fertilization – or, at the very least, that there are grounds for thinking that they existed as zygotes which do not apply to the prior egg cells. While this does not entail that human persons begin to exist at this point, it nevertheless has considerable significance for this latter question.

An omnipotent being would be a being whose power was unlimited. The power of human beings is limited in two distinct ways: we are limited with respect to our freedom of will, and we are limited in our ability to execute what we have willed. These two distinct sources of limitation suggest a simple definition of omnipotence: an omnipotent being is one that has both perfect freedom of will and perfect efficacy of will. In this paper we further explicate this definition and show that it escapes the standard objections to divine omnipotence.

Scoring rules measure the deviation between a credence assignment and reality. Probabilism holds that only those credence assignments that satisfy the axioms of probability are rationally admissible. Accuracy-based arguments for probabilism observe that given certain conditions on a scoring rule, the score of any non-probability is dominated by the score of a probability. The conditions in the arguments we will consider include propriety: the claim that the expected accuracy of _p_ is not beaten by the expected accuracy of any other credence _c_ by the lights of _p_ if _p_ is a probability. I argue that if we think through how a non-probabilist can respond to pragmatic arguments for probabilism, we will expect the non-probabilist to accept a condition _stronger_ than propriety for the same reasons that the probabilist gives for propriety, but this stronger condition is incompatible with the other conditions that the probabilist needs to run the accuracy argument. This makes it unlikely for the probabilist’s argument to be compelling.

The strict dominance principle that a wager always paying better than another is rationally preferable is one of the least controversial principles in decision theory. I shall show that (given the Axiom of Choice) there is a contradiction between strict dominance and plausible isomorphism or symmetry conditions, by showing how in several natural cases one can construct isomorphic wagers one of which strictly dominates the other. In particular, I will show that there is a pair of wagers on the outcomes of a uniform spinner which differ simply in where the zero degrees point of the spinner is defined to be but where one wager dominates the other. I shall also argue that someone who accepts Williamson’s famous argument that the probability of an infinite sequence of heads is zero should accept the symmetry conditions, and thus has reason to weaken the strict dominance principle, and I shall propose a restriction of the principle to “implementable” wagers. Our main result also has implications for social choice principles.

Scoring rules measure the deviation between a forecast, which assigns degrees of confidence to various events, and reality. Strictly proper scoring rules have the property that for any forecast, the mathematical expectation of the score of a forecast p by the lights of p is strictly better than the mathematical expectation of any other forecast q by the lights of p. Forecasts need not satisfy the axioms of the probability calculus, but Predd et al. [9] have shown that given a finite sample space and any strictly proper additive and continuous scoring rule, the score for any forecast that does not satisfy the axioms of probability is strictly dominated by the score for some probabilistically consistent forecast. Recently, this result has been extended to non-additive continuous scoring rules. In this paper, a condition weaker than continuity is given that suffices for the result, and the condition is proved to be optimal.