Alexander R. Pruss

Some, notably Peter van Inwagen, in order to avoid problems with free will and omniscience, replace the condition that an omniscient being knows all true propositions with a version of the apparently weaker condition that an omniscient being knows all knowable true propositions. I shall show that the apparently weaker condition, when conjoined with uncontroversial claims and the logical closure of an omniscient being's knowledge, still yields the claim that an omniscient being knows all true propositions.

The free-will defence (FWD) holds that the value of significant free will is so great that God is justified in creating significantly free creatures even if there is a risk or certainty that these creatures will sin. A difficulty for the FWD, developed carefully by Quentin Smith, is that God is unable to do evil, and yet surely lacks no genuinely valuable kind of freedom. Smith argues that the kind of freedom that God has can be had by creatures, without a risk of creatures doing evil. I shall show that Smith's argument fails – the case of God is disanalogous to the case of creatures precisely because creatures are creatures

          Despite the fact that the strength of argument is clearly on the pro-life side—nobody except a handful of academics would question the grave wrongness of abortion were pregnancy never inconvenient—somehow ordinary intelligent people, like our students, often remain unconvinced. There are many reasons for this, of course. For instance, a number of students have had their children aborted while many know others who have had abortions, and one does not want to condemn oneself or oneÂ’s friends. I am a philosopher, however, and so I will be interested in intellectual reasons, even though these subjective psychological ones are almost surely more important. Specifically, I will be interested in the fact that the ordinary person subscribes to a number of erroneous big-picture ethical beliefs, each of which, to a different degree, does something to block access to the pro-life arguments. I will not talk about all such erroneous beliefs and I would be grateful in the discussion for more examples.           I will talk about eight errors I have identified, largely through teaching. For each one, I will identify the error, show how it impacts the pro-life message and explain why it is tempting to most of us —there is, after all, something right about five of the errors. For each of these errors is one that we might ourselves be tempted by on occasion. I will then suggest some ways of refuting the error. In some cases, the mere identification of the error should do the trick, as these erroneous beliefs are often not explicitly identified by our interlocutors. My suggested refutations will not always be phrased in the way in which I would phrase them for didactic effectiveness: in this talk, I am mainly trying to convey ideas.

SpinozaÂ’s God is a being with infinite attributes, each of which expresses infinite essence. Does this mean that God has infinitely many attributes, each of which expresses infinite essence, or does God simply have attributes, each of which is infinite and expresses infinite essence? SpinozaÂ’s argumentation in Letter 9 and the Scholium to Prop. I.10 clearly indicates that it is not just each individual attribute that is infinite, but there are in some sense infinitely many of them. This would seem to settle the issue, except that Spinoza never talks of more than two attributes, Extension..

Consider the regularity thesis that each possible event has non-zero probability. Hájek challenges this in two ways: there can be nonmeasurable events that have no probability at all and on a large enough sample space, some probabilities will have to be zero. But arguments for the existence of nonmeasurable events depend on the axiom of choice. We shall show that the existence of anything like regular probabilities is by itself enough to imply a weak version of AC sufficient to prove the Banach–Tarski Paradox on the decomposition of a ball into two equally sized balls, and hence to show the existence of nonmeasurable events. This provides a powerful argument against unrestricted orthodox Bayesianism that works even without AC. A corollary of our formal result is that if every partial order extends to a total preorder while maintaining strict comparisons, then the Banach–Tarski Paradox holds. This yields an argument that incommensurability cannot be avoided in ambitious versions of decision theory

Consider the reasonable axioms of subjunctive conditionals if p → q1 and p → q2 at some world, then p → at that world, and if p1 → q and p2 → q at some world, then → q at that world, where p → q is the subjunctive conditional. I show that a Lewis-style semantics for subjunctive conditionals satisfies these axioms if and only if one makes a certain technical assumption about the closeness relation, an assumption that is probably false. I will then show how Lewisian semantics can be modified so as to assure and even when the technical assumption fails, and in fact in one sense the semantics actually becomes simpler then

Consider the following three-step dialectics. (1) Even if God (consistently) commanded torture of the innocent, it would still be wrong. Therefore Divine Command Metaethics (DCM) is false. (2) No: for it is impossible for God to command torture of the innocent. (3) Even if it is impossible, there is a non-trivially true per impossibile counterfactual that even if God (consistently) com­manded torture of the innocent, it would still be wrong, and this counterfac­tual is incompatible with DCM. I shall argue that the last step of this dialectics is flawed because it would rule out every substantive metaethical theory.

Patrick Toner has argued that eternalism, the doctrine that all times are ontologically on par, conflicts with the Catholic view of judgment as based on the state of the soul at death. For, he holds, it is arbitrary that judgment should be based on what happened at some particular time, unless, as presentism holds, that time is the only that really exists. I shall argue that his argument fails because the eternalist can say that judgment is simultaneous with the state of soul that is being judged, and there is nothing arbitrary about judging something at t on the basis of its state at the same time t.

I argue that standard functionalism leads to absurd conclusions as to the number of minds that would exist in the universe if persons were duplicated. Rather than yielding the conclusion that making a molecule-by-molecule copy of a material person would result in two persons, it leads to the conclusion that three persons, or perhaps only one person, would result. This is absurd and standard functionalism should be abandoned. Social varieties of functionalism fare no better, though there is an Aristotelian variety of functionalism that accepts irreducible finality that escapes this particular reductio.

The latter third of the 20th century has seen the philosophical defence of theism - many philosophers were caught off-guard because they assumed that metaphysics and theology had been dealt with. Moreover, the leaders of this renaissance were analytically-rooted philosophers. Upon examination however, it is clear that significant developments in philosophical theism historically have come upon the heels of breakthroughs in the core areas of philosophy concerning meaning, logic and scientific methodology - cornerstones of analytic philosophy. This volume attempts to document this golden era of analytical theism.

There is an important sense in which one can be sure without being certain, i.e., without assigning unit probability. I will offer an explication of this sense of sureness, connecting it with the level of credence that a rational agent would need to have to be confident that she won’t ever lose her confidence. A simple formal result then gives us an explicit formula connecting the threshold α for credence needed for confidence with the threshold needed for being sure: one needs 1−(1−α) to be sure. I then suggest that stepping between α and 1−(1−α) gives a procedure that generates an interesting hierarchy of credential thresholds.

One of the problems that Bayesian regularity, the thesis that all contingent propositions should be given probabilities strictly between zero and one, faces is the possibility of random processes that randomly and uniformly choose a number between zero and one. According to classical probability theory, the probability that such a process picks a particular number in the range is zero, but of course any number in the range can indeed be picked. There is a solution to this particular problem on the books: a measure that assigns the same infinitesimal probability to each number between zero and one. I will show that such a measure, while mathematically interesting, is pathological for use in confirmation theory, for the same reason that a measure that assigns an infinitesimal probability to each possible outcome in a countably infinite lottery is pathological. The pathology is that one can force someone to assign a probability within an infinitesimal of one to an unlikely event

Adhering to the traditional concept of omniscience lands Gale in the incoherence Grim’s Cantorian arguments reveal in talk of “all propositions.” By constructing variants and extensions of Grim’s arguments, I explain why various ways out of the incoherence are unacceptable, why theists would do better to adopt a certain revisionary concept of omniscience, and why the Cantorian troubles are so deep as to be troubles as well for Gale’s Weak PSR. I conclude with some brief reflections on method, suggesting that we pursue the full implications of Gale’s own revisionary remarks and replace his method of analytic argumentation with non-analytic revisionary theory-construction.