Selected Papers and Essays
For a list of publications, please see my CV. I've
also been blogging philosophically at AlexanderPruss.blogspot.com and prosblogion.ektopos.com. A
number of the papers here are works in progress. Comments are welcome, especially on the works
in progress. Click on the title of a paper if you want to read the
Quick links: [Metaphysics and logic]
[Philosophy of religion and
theology] [Ethics] [Mathematical
Philosophical and theological papers
Metaphysics, philosophy of language, formal
epistemology and logic
- "The Principle of Sufficient Reason and Probability", Oxford Studies in Metaphysics (forthcoming).
I offer an argument for the Principle of Sufficient Reason on the basis of probabilistic reasoning in science.
- “Counterfactuals, Vagueness and God”.
functions, uniform distributions and infinite sequences of heads”,
forthcoming in the Journal of
Philosophical Logic. I show that invariant full conditional
probabilities are untenable in dimensions two and higher.
- “Regular probability comparisons
imply the Banach-Tarski Paradox”, forthcoming in Synthese. I show that
the existence of regular probability measures (hyperreal, conditional or
comparative) imply the Banach-Tarski Paradox.
proved”, forthcoming in the Canadian
Journal of Philosophy. I show that the transfer principle in the
consequence argument for incompatibilism follows (given a plausible
definition) from the rule of weakening for subjunctive conditionals.
- “Infinitesimals are too small for
countably infinite fair lotteries”, Synthese. Infinitesimals are too small to be the probability
of winning a countably infinite fair lottery.
asserting what you do not believe”, Australasian Journal of Philosophy. Examples show that one can
sincerely assert what one does not believe—in some odd situations.
lotteries, perfectly thin darts and infinitesimals”, forthcoming in Thought. Using infinitesimals to
model the results of dart throws and the like leads to serious problems.
- "A Deflationary Theory of Diachronic
Identity", Australasian Journal of Philosophy. I defend a theory of
diachronic identity guaranteed to have no counterexamples and superior to
Intelligence and Personal Identity", appeared in Faith and
Philosophy. I argue that absurdities follow from the assumption that a robot
is a person.
- "Identity and the Copying of
Minds". I argue against psychological theories of identity that claim that
in cases where one's personality and memories are moved into the brain of
another, we move with them. I am not entirely convinced by my arguments
here, I must confess, but I think they deserve some thought.
Determinism and Gale's Principle." I give an argument for incompatibilism on the basis of a plausible
supervenience principle and a weakened version of Gale's principle that if
all my actions were intentionally caused by another person, then none of
my actions were free.
- "Special Relativity and
identify a fallacy in Hales and Johnson's argument that endurantism is
incompatible with special relativity and argue that an improvement on
their argument also does not succeed.
- "Processes, Marks and
give a simple counterexample to Salmon's account of causal processes in
terms of mark transmission. The example has the advantage that not
only does it appear to qualify as transmission of a mark under Salmon's
definition of mark transmission, but it appears to actually be an instance of mark transmission.
- "Animalism and Brains".
I argue that it is possible for a
human animal to survive the loss of all bodily parts other than the brain.
Language and Ethics", Philosophy of Time Group Meeting, Eastern
- The Principle of
Sufficient Reason: A Reassessment, Cambridge University Press, in
2006. No longer available online, but can be purchased from amazon.com.
Nihilo Nihil Fit: Arguments New and Old for the Principle of
Sufficient Reason", presented at the American Catholic
Philosophical Association meeting, Cincinnati, November, 2002
on John Haldane's 'The Soul'", presented in Pittsburgh, April 5,
2003. (Handout is also available.)
Worlds: What They Are Good For and What They Are. Doctoral
Dissertation, University of Pittsburgh, 2001.
- "The Actual and the Possible."
In Richard M. Gale (ed.), Blackwell Guide to Metaphysics, Oxford:
Blackwell, 2002. A
discussion of two contemporary views of the nature of possibility and
possible worlds, and a theistic alternative. Includes a new version
of the Third Way, and ethical objections to David Lewis's extreme modal
Lewis's Counterfactual Arrow of Time." Published in Nous.
I argue that David Lewis's
counterfactual account of the direction of time fails in a number of
cases, and in other cases only succeeds because the cases are chosen by us
in ways that cohere with our time-reversal-asymmetric concerns.
Subjunctive Conditional Law of Excluded Middle." Work in
progress. This Law
claims that for any pair of propositions p and q, it is true that were
p to hold, q would hold or it is true that were p to hold, not-q
would hold. I show that given plausible suppositions the Law is
Cardinality Objection to David Lewis's Modal Realism." Philosophical
Studies 104 (2001) 167-176. The collection of all possible worlds is too large to have
cardinality and hence possible worlds cannot be existent concrete
Are Aristotelian Forms?" Early version of paper forthcoming in Analysis and Existence. Prescinding from detailed exegesis of texts, what kind of an
entity is an Aristotelian form? Can the notion be made intelligible
in a contemporary setting? What would one be saying about the world
by saying that there are Aristotelian forms?
Alien Properties and Laws of Nature" A criticism of recombinationist
theories of possibility, and an argument against views that utterly reject
and Counting Minds." Work in progress. In
general there is no fact of the matter as to how many machines are
computing any given program. Since there plainly is a fact of the
matter as to how many persons are conscious in a given way, it follows
that being a conscious person is not simply a matter of being an
appropriate computing system.
Two Equal Infinity? The Attributes of God in Spinoza."
Work in progress. Spinoza's God has "infinite attributes",
even though only Extension and Thought are mentioned explicitly? I
argue that Spinoza, given his commitment to the truthmaker principle that
any true proposition is made true by something positive, can neither say
nor deny that Extension and Thought are the only two attributes. I
end with a truthmaker-based ontological argument for the existence of God
that might be of interest independently of Spinoza.
Semantics for Subjunctive Conditionals and Some Plausible Rules of
Inference." [PDF] Forthcoming in Synthese. I show that on a plausible
interpretation of the closeness relation between worlds, Lewis's account
of subjunctive conditionals fails to support two obvious rules of
inference concerning conjunctions of consequents or disjunctions of
antecedents. I offer a modification of Lewis's semantics that solves
this problem, but note that some difficulty still remains. I also
characterize when the subjunctive conditional law of excluded middle holds.
- "Causation and the Arrow of Time."
I argue that the direction of
time probably supervenes on the directions of causal relations.
Philosophy of religion and
- “Divine Creative Freedom.” In J.
Kvanvig (ed.), Oxford Studies in the
Philosophy of Religion, volume 7. I argue that massive incommensurability
helps explain the freedom of God’s decision what world to actualize.
- “A Gödelian ontological argument improved even
more.” In M. Szatkowski (ed.), Ontological Proofs Today, 2012.
restricted to full omniscience", Religious Studies
(2010). I show that if God knows every truth that he can know, then
God knows every truth.
counterexample to Plantinga's Molinist Free Will Defense"
- "The Ontological Argument and
Motivational Centres of Lives" I argue that a proposition
belief in which is at the motivational center of a flourishing life is
probably possibly true, in at least one of the two-dimensionalist kinds of
modality. Since there are flourishing lives at whose motivational center
is the proposition that there is a maximally great being, the possibility
premise of the ontological argument is probably true, and hence, at least
probably, there is a God.
cosmological arguments." Forthcoming in the Blackwell
Companion to Natural Theology.
- "The Essential Divine Perfection
Objection to the Free Will Defense" Accepted for publication in Religious
Studies. I shall argue that Quentin Smith's objection to the Free
Will Defense on the grounds that God can be free even though he cannot but
act rightly fails; caused beings are disanalogous to uncaused beings.
- "A Goedelian Ontological Argument
Improved" Accepted for publication in Religious Studies. I
give an improved version of Goedel's ontological argument, using weaker
axioms and escaping Oppy's criticisms.
- "Love and Obedience" I give
an account showing how duties of love entail duties of obedience,
especially where the beloved is God.
we prevent evil if sceptical theism is right?" I argue that
the answer is affirmative, pace Oppy.
- "Some recent progress on the
cosmological argument." [PDF] Presented at the Two Tasks
Conference, Alexandria, Virginia, June, 2006.
- "How not to reconcile evolution
and creation." Presented at the University of Notre Dame,
March 8, 2006.
- "Altruism, Teleology and
God." [PDF] Presented at the Harvard Divinity School, December,
Cosmos as a Work of Art." Presented at Epiphanies of Beauty
conference, University of Notre Dame, November, 2004.
without Middle Knowledge." Accepted for publication in Faith
and Philosophy subject to revision. I argue that the best
available way to solve the problems with how prophecy works given
Middle Knowledge requires the invocation of a principle of relevant
similarity which states that an agent would have acted in the same
way had the circumstances been relevantly similar. But if one is
willing to allow this for a fairly lax measure of relevant similarity,
then one can get prophecy without Middle Knowledge, assuming only
Bugs, DNA and a Design Argument." I give an analogical
argument for the existence of a designer of our DNA based on the
applicability of the concept of a genetic disorder.
- "Can one infer design without knowing
the function or purpose of a thing?" While the principle
still seems plausible to me, in this very short "paper" I
present an apparent counterexample.
- "On Three Problems of
Divine Simplicity." Presented at the Society of Christian
Philosophers satellite session at the American Catholic Philosophical
Association meeting, 2003. I consider three of the most serious
philosophical objections to the doctrine of divine simplicity and offer
reflections that make these objections less poignant, and that in fact
suggest that the incoherence claimed to be there might not be there.
- "Fine and Coarse Tuning,
Renormalizability and Probabilistic Reasoning." Presented
at a workshop on fine-tuning, Notre Dame University, April, 2003.
on Alvin Plantinga's 'Games Scientists Play'." Presented in
Pittsburgh, April 5, 2003 at a conference in honor of Richard M.
Gale. (Handout is also available.)
Restricted Principle of Sufficient Reason and the Cosmological
Argument." Accepted by Religious Studies. Some
people reject the Principle of Sufficient Reason (PSR) because of apparent
counterexamples like libertarian free will, quantum mechanics or the
conjunction of all contingent propositions. I offer a natural
restriction of the PSR that takes care of all such supposed
counterexamples, a restricted version nonetheless sufficiently strong to
ground a Cosmological Argument.
New Free Will Defense." Forthcoming in Religious Studies.
If creatures are to have significant free will, then God's essential
omnibenevolence and essential omnipotence cannot logically preclude him
from creating a world containing a moral evil. This is argued for
with no reliance on subjunctive conditionals of free will, but in several
independent ways based on premises that many will accept.
- With Richard M. Gale. "A Response to Almeida and Judisch."
International Journal for the Philosophy of Religion (forthcoming).
A response to some criticisms of our new cosmological argument.
- With Richard M. Gale. "A New Cosmological Argument." Religious
Studies 35 (1999) 461–476. For every true proposition
p, possibly p has an explanation. We argue from this weak version of
the principle of sufficient reason that there exists a powerful and
intelligent Designer-Creator of the universe.
Faith and Belief." Forthcoming in Faith and Philosophy.
Louis Pojman (as well as others in different ways) has claimed that a
Christian does not need to believe the propositions of the Christian faith
even with epistemic probability 1/2. However, once we consider the
nature of ethical decision making in cases of uncertainty about moral
principles, we see that for many if not most Christians a commitment to
acting in Christian ways requires assigning an epistemic probability of at
least 1/2 to Christianity.
Paradox, Reason, and the Argumentum Spiritus Sancti in Climacus and
Kierkegaard." (Short version.) Presented at the
meeting of the Soren Kierkegaard society at the 2001 Central APA. This
is a pseudonymous production, mirroring the pseudonymous productions of
Kierkegaard, exploring both the nature of the absurdity involved in faith
according to Climacus and Kierkagaard as well as broader issues of the
interpretation of the Concluding Unscientific Postscript.
Paradox, Reason, and the Argumentum Spiritus Sancti in Climacus and
Kierkegaard." (Long version.)
Principle and Two Ontomystical Arguments." International
Journal for Philosophy of Religion 49 (2001) 111-120. Two
ontological arguments are given, one of them apparently new, and the
crucial possibility premises in them are argued for on the basis of
Religious Experience Argument for the Existence of a Transcendent Holy
Being." Work in progress. Experiences fall
into irreducible classes. Any class of actual cognitive experiences
contains an experience which is right, in the sense that it is veridical
or at least that which it purports about reality is indeed so.
Mystical experiences of a transcendent holy being constitute a class of
cognitive experiences. Hence there is a transcendent holy being.
proof of the existence of God." A summary of Meyer's
attempt at proving the existence of God by means of a strong causal
principle and Zorn's Lemma from set theory.
Unwritten Esther." A short prize-winning essay on the
Book of Esther.
and Union", talk for a workshop on the work of Nicholas
Wolterstorff, Baylor University, 2009
Body: Reflections on Christian Sexual Ethics", talk at the
University of St Thomas, Houston, TX, 2008
Also With Evildoers", Society of Christian Philosophers Eastern
Division Meeting, 2008
- "Plans and their Accomplishment",
Maritain Society Group Meeting, Eastern APA, 2006
- "Cooperation with past evil and
use of cell-lines derived from aborted fetuses." I argue
for a moderate position on which the use of such cell-lines has a
presumption against it, but is not absolutely forbidden. At the same
time, I analyze why precisely there is such a presumption. This
analysis has interesting connections with the retributive theory of
- "Love and Double Effect."
Presented at the Formation and Renewal Conference, Notre Dame University,
Tempting Big-Picture Errors in Ethics." Presented at the
University Faculty for Life Conference, Georgetown University, May 31,
Maxims and Lying." Work in progress. Christine
Korsgaard argued that Kant's first Categorical Imperative (CI) allows you
to lie to people who try to deceive you about their intentions. I
argue that Korsgaard's argument rests on what appears to be a subtle
misunderstanding of the nature of a Kantian maxim.
- "Lying, Deception and Kant."
Work in progress. A common objection to Kant is that his
view prohibits lying under all circumstances. But there is a
distinction between lying and deception, and some forms of deception are
clearly permissible. A more serious objection to Kant is that his
view prohibits all deception.
Out of Lust But in Accordance With Truth: Theological and Philosophical
Reflections on Sexuality and Reality." Forthcoming in
Logos. An account of Christian sexual ethics centered on the
notion of truth and reality.
Sexual Ethics and Teleological Organicity." The Thomist
64 (2000) 71-100. An account of Christian sexual ethics,
particularly focusing on the immorality of contraception, centered on an
analysis of the unitive dimension of sexuality and an argument that the
unitive dimension is dependent on the procreative.
- "Lying and
speaking your interlocutor's language." [Link might work
only if your institution subscribes to The Thomist.] The Thomist
63 (1999) 439-453. If one ought not lie even to the
Gestapo officer at the door when one is hiding Jews, what should one do?
was once a fetus: an identity-based argument against abortion."
Work in progress. To kill me earlier in my life inflicts a
greater harm on me by depriving me of more. I was once a
fetus. Therefore, to have killed me then would have deprived me of
more than to have killed me now. Since it is the harm to me that
makes it wrong to kill me now, it would have been wrong to kill me when I
was a fetus. I also give a Rawlsian argument against abortion based
the claim that I was once a fetus. Most of the paper is a defense of
the claim that I was once a fetus.
- "I was once a fetus: that is why
abortion is wrong." Work in progress. A
shorter variant of the above argument.
- "Maternal love and
abortion." Work in progress. Some people
are opposed to abortion in general because they loved their children when
these were fetuses. While this may be a psychological explanation of
why these people believe thus, and perhaps an argument for these people
not to abort the children they love, it does not at first sight seem to be
an argument for the prima facie wrongness of abortion in general, and
especially not an argument that other people have any reason to pay
attention to. I will argue that on the contrary the phenomenon of
mothers loving their unborn children gives one a significant reason to
think abortion to be prima facie wrong in general.
- “Linear extensions of orders invariant
under abelian group actions.”
- “On the Law of Large Numbers for
Nonmeasurable Identically Distributed Random Variables.” Forthcoming in the Bulletin of the Polish Academy of Sciences, Mathematics.
Green's Functions, Harmonic Measures and Difference Equations.
Doctoral dissertation, University of British Columbia, 1996. In
- "A general
Hsu-Robbins-Erdos type estimate of tail probabilities of sums of
independent identically distributed random variables."
Draft of a paper forthcoming in the Periodica Mathematica Hungarica.
A very general theorem characterizing the convergence of sums of terms of
the form tnP(|X1+...+Xn|>ean) where X1,...,Xn
are independent and identically distributed.
- "From the
Polya-Szego symmetrization inequality for Dirichlet integrals to comparison
theorems for p.d.e.'s on manifolds." Presented at the 8th
Symposium on Classical Analysis, Kazimierz Dolny, Poland, September,
1995. A method for proving symmetrization inequalities for some
elliptic p.d.e.'s on manifolds equipped with appropriate isoperimetric
inequalities is outlined.
- With Stephen Montgomery-Smith.
inequality for sums of independent random variables." Journal
of Mathematical Analysis and Applications 254 (2001) 35-42.