Tuesday, May 11, 2021

The weird view that particles don't survive substantial change

I have a weird view: when a dog or another substance ceases to exist, all its particles cease to exist, being replaced by new particles with very similar physical parameters (with the new physical parameters being predictable via the laws of nature). Similar things happen when a new substance comes into existence, and when a particle is incorporated into or leaves a substance: no particles survive such things.

I have good Aristotelian reasons for this view. Particles are not substances, since substances cannot have substances as parts, and hence ontologically depend on substances for their existence. Thus, when the substance perishes, the particles do as well.

The view seems preposterously unparsimonious. I disagree. Let’s compare the view to some competitors. First of all, it’s clear to me that some version of four-dimensionalism is true, so let’s start with four-dimensionalist views.

A standard four-dimensionalism is perdurantism: four-dimensional objects are made up of instantaneous temporal parts—infinitely many of them if time is continuous. These instantaneous temporal parts come in and out of existence all the time, with very similar physical parameters to their predecessors. My weird view is compatible with the idea that particles actually all exist only instantaneously, akin to the perdurantist’s temporal parts. Such a view could be more parsimonious than standard perdurantism for two reasons: first, it needn’t posit temporal parts of substances, and, second, it needn’t posit wholes made up of the instantaneous particles.

An alternate version of my weird view says that particles do not survive change of substance, but live as long as they recognizably remain in the same substance. Imagine a particle that is eaten by a dog and some months later sloughed off. On my view, there are three particle-like objects in the story: the pre-dog particle, the in-dog particle, and the post-dog particle. On standard perdurantism, there are as many particle-like objects as moments of time in this story. Granted, some may think it weirder that the temporal boundaries in the existence of particles are determined by their allegiances to substances rather than by instants of time. But there is nothing weird about that if one takes seriously the priority of substances to their parts.

My view is admittedly less parsimonious than a four-dimensionalist view on which substances and particles are temporally extended, have no temporal parts, and particles outlast their substances. But such a four-dimensionalist has an implausible consequence. Many people will find plausible the idea that in some exceptional cases substances can share parts: conjoined twins are a standard example. But on this version of four-dimensionalism, it is now a matter of course that distinct substances share parts. The dog dies and some of its particles become a part of a flower: so the dog and the flower, considered as four-dimensional entities, have these particles as common parts. You and I share probably share parts with dinosaurs. So while my weird view is less parsimonious than a no-temporal-parts four-dimensionalism with particles that outlive substances, it is not less plausible.

The main alternative to four-dimensionalism is presentism. Is a presentist version of my view less parsimonious than a typical competing presentist view? In one sense, not. For at the present time, my view doesn’t posit additional present particles over and beyond those present particles posited by competing presentist views. And only present particles exist according to presentism! But more seriously, my view does posits that particles cease to exist and come into existence more than on typical presentist alternatives. So in that sense it is less parsimonious.

Thus, parsimony cuts against my view on presentism, but it may actually favor it on four-dimensionalism.

Monday, May 10, 2021

Is our universe of sets minimal?

Our physics is based on the real numbers. Physicists use the real numbers all over the place: quantum mechanics takes place in a complex Hilbert space, and the complex numbers are isomorphic to pairs of real numbers, while relativity theory takes place in a manifold that is locally isomorphic to a Lorentzian four-dimensional real space.

The real numbers are one of an infinite family of mathematical objects known as real closed fields. Other real closed fields than the real numbers could be used in physics instead—for instance, the hyperreals—and I think we would have the same empirical predictions. But the real numbers are simpler and more elegant: for instance, they are the only Dedekind-complete and the minimal Cauchy-complete real closed field.

At the same time, the mathematics behind our physics lives within a set theoretic universe. That set theoretic universe is generally not assumed to be particularly special. For instance, I know of no one who assumes that our set theoretic universe is isomorphic to Shepherdson’s/Cohen’s minimal model of set theory. On the contrary, it is widely assumed that our set theoretic universe has a standard transitive set model, which implies that it is not minimal, and few people seem to believe the Axiom of Constructibility which would hold in a minimal model.

This seems to me be rationally inconsistent. If we are justified in thinking that the mathematics underlying the physical world is based on a particularly elegant real closed field even though other fields fit our empirical data, we would also be justified in thinking it’s based on a particularly elegant universe of sets even though other universes fit our empirical data.

(According to Shipman, the resulting set theory would be one equivalent to ZF + V=L + “There is no standard model”.)

Friday, May 7, 2021

From naturalism to divine command theory by way of vagueness


  1. There is a collection K of atoms forming an early stage of the developmental history of a particular human, where it is vague whether it is morally permissible to disperse the atoms in K.

Pro-choice readers might take K to be the collection of atoms in a late fetus or an early newborn. Pro-life readers might take K to be the collection of atoms at some early point during the fusion of gametes. (Note that (1) does not say that the atoms in K form a human.)

It is widely held that:

  1. Vague matters always depend on semantic plasticity.


  1. Whether it is permissible to disperse the atoms in K does not depend on any semantic questions.

Claims (1)–(3) look incompatible. So we should abandon at least one of them. Personally, as a pro-life Aristotelian dualist, I am happy to abandon (1)—whether it is permissible to disperse the Ks depends on whether there is a human form uniting the Ks, and that’s not a vague matter. But apart from a Markosian-style brute fact view of composition—a view that seems implausible—it seems hard for a naturalist to deny (1).

Claim (2) is pretty plausible.

This means that if we accept (1), we should deny (3). But how to deny (3)? How could the question of whether it is permissible to disperse the atoms at some developmental stage depend on semantic questions? Surely it is a totally abhorrent idea that whether it is acceptable to disperse the atoms in K is determined by our linguistic performances?

Indeed! But it need not depend on the semantics of our linguistic performances. There is exactly one major moral theory that make that allows for a reasonable denial of (3): divine command theory. Commands are linguistic performances. Whether some act violates a command is in part a linguistic matter. Given divine command theory, semantic plasticity in the terms of the commands can ground vagueness in the obligations constituted by the commands. If your commander says: “Shave until you’re bald”, your obligation seems to be vague precisely because of the vagueness of language.

And that the semantics of God’s linguistic performances matters to the right to life of K is far from as objectionable as some claim on which our linguistic performances have the determining role. (Though our linguistic performances have some role to play, since they may help define the words that God is using if God speaks our language.) Thus, we can imagine that God says: “Thou shalt not murder.” But perhaps “murder” is vague. And the vagueness in this word then translates to vagueness as to whether the dispersal of the atoms in K is permissible.

If the above is right, then we have an argument for a very surprising thesis:

  1. If physicalism (about us) is true, then divine command theory is the correct moral theory, and hence God exists.

This is yet another in a series of observations that I’ve been making over the years, that theistic naturalism has resources that its atheistic cousin lacks.

All that said, I think physicalism (even about us) is false, and divine command theory is not the correct moral theory. Though I do think God exists.

Vagueness about moral obligation

There is a single normative property that is normatively above all others, that overrides all others: moral obligation.

I think the above intuition entails that there cannot be any non-epistemic vagueness about moral obligation.

There are two main non-epistemic approaches to vagueness: deviant logic and supervaluationism. Deviant logic is logically unacceptable. :-) That leaves supervaluationism. But on supervaluationism, there would have to be many acceptable precisifications of our concept of moral obligation. Each such precisification would presumably be a normative property. But only a precisification that was normatively above all others could be an acceptable precisification of our concept of moral obligation. And there can only be one precisification above all others. So there can only be one acceptable precisification of moral obligation.

The above argument is too quick. The supervaluationist can say that in the claim “Moral obligation is above all other normative properties”, we have another candidates for vagueness: “above” (or “overrides”). Then we need to engage in coordinated precisification of “moral obligation”, as well as “above”. For each coordinated precisification, the aboveness claim will be true: “Moral obligationi is abovei all other normative properties.”

I think, however, that once we allow for a variety of precisifications of “above”, we betray the intuition behind the aboveness thesis. That in some sense moral obligation is above personal convenience is not the bold and bracing intuition of the overridingness of morality. Thus, I think that if we are to be faithful to that intuition, we cannot allow for non-epistemic vagueness about moral obligation.

And this, in turn, greatly limits how much non-epistemic vagueness there can be. For instance, if there is no vagueness about permissibility, then it cannot be vague whether something is a person, since vagueness about personhood leads to vagueness about moral obligations of respect. Indeed, it is not clear that there can be any non-epistemic vagueness if there is no non-epistemic vagueness about moral obligation. Suppose I promise to become bald, and I have a small amount of hair. Then I am non-bald if and only if I am obligated to remove some hair.

Personal escape?

I'm now fully vaccinated, so through the wonders of modern medicine I'm deeming myself to have likely escaped COVID-19, while sadly aware that so much of the world is still struggling (I pray that vaccine patent waivers will go through and help).

I've been so very fortunate, unlike so many. Starting with August, the pandemic had little negative personal impact. On the contrary, being masked and distanced made me feel more comfortable around other people, and having conference and lecture travel be replaced with online events was wonderful. It would be great, for convenience, cost and environmental reasons, if conferences continued online indefinitely, hopefully with technical progress on getting informal interactions working better. (My experience is that the formal discussions at conferences are intellectually every bit as good when online, at least when the same people are in attendance.)

Since April 2020, I had exactly four occasions where I was within two meters of someone not from my household for 15 minutes or more in a 24-hour period. Two of them were dental visits. And two were Uber rides between home and the car repair shop. For the two Uber rides, I wore my "industrial-looking" elastomeric 3M P100 respirator (with an added exhalation filter), so I was quite safe--alas, it wasn't practical to do that for the dental visits.

For church and grocery stores, I usually used the 3M respirator. For the gym, I have a Trend woodworking N100 respirator (eventually modified to remove valves and block the exhale port). In both cases, I was quite safe and so were others around me.

Apart from one lecture moved online due to snow and one online due to a false COVID alarm (on the basis of two negative tests, I eventually concluded it was just a bad cold), I taught in person in both fall and spring. For teaching, I used cheap but heavily modified five-layer KN95 masks, because I was much more audible through them than through cloth, not to mention elastomeric respirators. Of course, I usually had some students Zooming in, often for COVID-related reasons but sometimes probably for more minor reasons.

I am not quite sure how I will modify my protocols now that I am fully vaccinated. My 3M and Trend elastomeric masks are very breathable, and keep the filter material away from my sweaty face, so I may end up still using the Trend mask for the gym. I may replace its N100 filters with 3D printed filters based on surgical mask material, though. I have considered continuing social distancing for the rest of my life in order to reduce the transmission of all respiratory diseases. Neither the flu nor even the common cold are enjoyable, and my personal utilities are such that if social distancing were to prevent the flu, it would be worth it, since given my white collar occupation and given that I live in a smallish town, it's only a slight inconvenience to distance myself under most circumstances, and it's intrinsically pleasant to have more personal space. However, since other people in my household aren't going to distance themselves from strangers once the pandemic is over, I suspect that my personal distancing would not do much to keep me from getting respiratory diseases at that point. I may make an effort to try for at least a meter of distance in most circumstances when interacting with people outside the household--but that is anyway within the range of North American proxemic zones.

Wednesday, May 5, 2021

Unicorns and error theory

Kripke famously argued that unicorns cannot exist. For “unicorn” would have to refer to a natural kind. But there are multiple non-actual natural kinds to which “unicorn” could equally well refer, since it’s easy to imagine worlds w1 and w2 in each of which there is a natural kind of animal that matches the paradigmatic descriptions of unicorns in our fiction, but where the single-horned equines of w1 are a different natural kind (at the relevant taxonomic level) from the single-horned equines of w2. The proposition p expressed by “There are unicorns” is true in one of the worlds but not the other, or in both, or in neither. Symmetry rules out its being true in one but not the other. It can’t be true in both, because then “unicorn” would refer to two natural kinds (at the relevant taxonomic level), while it arguably refers to one (at least if we index it to a sufficiently specific body of fictional work). So, the proposition must be true in neither world, and by the same token, there will be no world where it’s true.

It seems to me, however, that rather than saying that the proposition expressed by “There are unicorns” is impossible, we should say that “There are unicorns” fails to express a proposition. Here’s why. We could imagine Rowling enriching the Harry Potter stories by introducing a new species of animals, the monokeratines. Suppose she never gives us enough detail to tell the two species apart, so all the descriptions of “unicorns” in her stories apply to “monokeratines” and vice versa, but she is clear that they are different species (perhaps the story hinges on one of them being an endangered species and the other not).

Now, if “There are unicorns” in these (hypothetical) stories expresses a proposition, so does “There are monokeratines”. But if they express propositions, they express different propositions (neither entails the other, for instance). Thus, suppose “There are unicorns” expresses p while “There are monokeratines” expresses q. But no reason can be given for why it’s not the other way around—why “There are unicorns” doesn’t express q while “There are monokeratines” expresses p. In fact, the exact same reasoning why Kripke rejected the hypothesis that “There are unicorns” is true in one of w1 and w2 but not in the other applies here. Thus, we should reject the claim that either sentence expresses a proposition.

But if we do that, then we should likewise reject the claim that in the actual world, where Rowling doesn’t talk about monokeratines, “There are unicorns” expresses p (say). For it could equally well express q.


But maybe there is another way. One could say that “There are unicorns” is vague, and handle the vagueness in a supervaluationist way. There are infinitely many species u such that “There are unicorns” can be taken to be precisified into expressing the proposition that there are us. Thus, there is no one proposition expressed by the sentence, but there are infinitely many propositions for each of which it is vaguely true that the sentence expresses it.

This might be a good response to my old argument that error theorists should say that “Murder is wrong” is nonsense. Maybe error theorists can say that “Murder is wrong” has infinitely many precisifications, but each one is false, just as “There are unicorns” has infinitely many precisifications, but each one is false.

This suggests a view of fiction on which claims about fictional entities always suffer from vagueness.

An interesting thing is that on this approach, we need to distinguish between in-story and out-of-story vagueness. Suppose a Rowling has a character say “There are unicorns.” In-story, that statement is not vague. I.e., according to the story there is a specific species to which the word “unicorn” as spoken by the character definitely refers. But out-of-story, we have vagueness: there are infinitely many possible species the claim could be about.

This suggests that the error theorist who takes the vagueness way out is not home free. For it is a part of our usage of “(morally) wrong” that it refers fairly unambiguously to one important property. But the error theorist claims vagueness. If the statements about wrongness were made in a story, then the error theorist could handle this by distinguishing in-story and out-of-story vagueness. But this distinction is not available here.

A similar problem occurs for a real-world person who claims that there are unicorns. Maybe one could say that the person intends in saying “There are unicorns” to express a single specific proposition, but fails, and vaguely expresses each of an infinity of propositions, all of them false. If so, then a similar move would be available to the error theorist. But I am sceptical of this move. I wonder if it’s not better to just say that “There are unicorns” as said by someone who intended to express an existential claim about a single definite species is nonsense, but there is a neighboring sentence, such as “There is an extant species of single-horned equines”, that makes sense and is true.

Monday, May 3, 2021

A constraint on metaethics

Suppose that we lived lives like ours in a world (possible or not) whose metaphysics included nothing like moral duties except that there was a loving God and he issued commands. If in that world we used the phrase “morally wrong”, that phrase would refer to the property of being forbidden by God.

Or suppose that we lived lives like ours in a world (possible or not) whose metaphysics included nothing like moral duties except that we had Aristotelian forms and they specified what the will should will, the phrase “morally wrong” would refer to the property of being contrary to what our form says the will should will.

But suppose now we lived in a world where there was nothing like moral duties, no God, no forms, but buried underground and unseen by humans there was a stone tablet that arose from a random volcanic process millions of years ago. On these tablets by chance there were markings that looked just like French sentences, and when interpreted as French sentences, they stated imperatives, like the Golden Rule, that that fit very well with our intuitions about what are the core moral duties. I doubt that the phrase “morally wrong” would refer to the property of being contrary to what the stone tablet would enjoin if it were interpreted as French. (I am careful in my wording, because strictly speaking the stone tablet, being the product of random processes, does not contain any sentences—it only contains markings that look like sentences of French.)

Suppose my intuition is right. What is the difference between the third case and the first two? Here is a hypothesis. In the divine command world, presumably our beliefs about what we call “morally wrong” have some sort of a connection to the commands of that God. In the Aristotelian world, our beliefs about the “morally wrong” presumably come in some way from the Aristotelian forms. But in the stone tablet world, the “morally wrong” beliefs have no connection to the stone tablets, except that the stone tablets happen to fit them.

This suggests an important constraint on metaethics: our beliefs about the morally wrong had better have a real connection—perhaps even a real causal connection—with their grounds. If this constraint is right, then evolutionary debunking arguments against morality cut more deeply than is recognized: if the arguments correctly show that our “moral concepts” lack a relevant connection with any grounds, then our “moral beliefs” not are not knowledge, but they are in fact just nonsense.

Of course, I want to turn this around: given that our moral beliefs are not mere nonsense, it follows that they have a real connection with grounds, and this undercuts the idea that we are mere products of completely unguided evolution.

A Biblical argument for epistemicism

  1. If God knows the exact number of hairs we have on our head, then there is a definite number of hairs we have on our head.

  2. If there is a definite number of hairs we have on our head, vagueness is at most epistemic.

  3. God knows the exact number of hairs we have on our head. (Luke 12:7)

  4. So, vagueness is at most epistemic.

Premise 2 is based on observing that the number of hairs we have on our heads involves similar kinds of vagueness to more paradigmatic cases of vagueness. Think here about these questions:

  • What’s the cut-off between hairs on the head and hairs on the upper neck?

  • How much keratin needs to come out of a hair follicle before that keratin counts as a hair?

  • How far must the molecules of a hair separate from the molecules of the skin before the hair counts as no longer attached?

One might worry that Premise 3 relies on biblical data too literalistically. Jesus is emphasizing the impressiveness of God’s knowledge. Suppose that instead of God knowing the exact number of hairs on my head, God knew the exact vagueness profile for the hairs on my head. That would be even more impressive. I see some force in this objection, but it implies that epistemicism holds at the level of vagueness profiles, and it seems (but perhaps isn’t?) ad hoc to go for epistemicism there rather than everywhere.

On reflection, I think premise 1 might be the most questionable premise. Perhaps God’s knowledge definitely matches the number of hairs: for every natural number n, it’s definitely true that: God believes I have n hairs if and only if I have n hairs, but there is no natural number n such that God definitely believes I have n hairs. In other words, the vagueness profile concerning God’s beliefs exactly matches the vagueness profile in reality. I am sceptical of this solution. It doesn’t feel like knowledge to me if it’s got this sort of vagueness to it.

Monday, April 26, 2021

If materialism is true, God exists

Causal finitism is the doctrine that backwards infinite causal histories are impossible.

  1. If the xs compose y, then y cannot have caused all of the xs.

  2. If materialism is true and causal finitism is false, then it is possible to have a human being that (a) is composed of cells and (b) caused each of its cells via a backwards infinite regress.
  3. So, if materialism is true, causal finitism is true. (1, 2)

  4. If causal finitism is true, then God exists.

  5. So, if materialism is true, God exists. (3, 4)

  6. If God exists, the materialism is false.

  7. So, materialism is false. (5, 6)

Premise (1) is a strengthening of a plausible principle banning self-causation.

Premise (2) follows from the fact that we are causes of all our present cells. If presentism is true, that completes the argument against materialism as in my previous post. But if eternalism or growing block are true, then we may also be composed of our past cells. And we didn’t cause our first cells. However if causal finitism is false, then it’s very plausible that backwards infinite causal regresses are possible, and so we could have existed from eternity, continually producing new cells, with the old ones dying.

Premise (4) is backed by a version of the kalaam argument.

Premise (6) is definitional if we understand materialism strongly enough to apply not just to us but to all reality. If we understand materialism more weakly, then the argument “only” yields the conclusion (5) that if materialism is true, God exists.

If presentism is true, materialism is false

  1. If the xs compose y, then y cannot have caused all of the xs.

  2. I caused all my present cells.

  3. If presentism is true, then all my cells are present cells.

  4. So, if presentism is true, then I caused all my cells. (2, 3)

  5. If materialism is true, then I am composed of my cells.

  6. If materialism is true, then I did not cause all of my cells. (1, 5)

  7. So, if presentism is true, materialism is not true. (4, 6)

At least sometimes parts aren't prior to wholes

  1. Efficient causes are explanatorily prior to their effects.

  2. Circularity of explanatory priority is impossible.

  3. I am the efficient cause of my teeth—I grew them!

  4. Therefore, my teeth are not explanatorily prior to me. (1–3)

  5. My teeth are parts of me.

  6. Therefore, at least some parts are not explanatorily prior to the wholes. (4, 5)

Friday, April 23, 2021

Why I can't believe in a God other than of classical theism

I can’t get myself to believe in a God who is an old bearded guy in the sky. That would be just a fairy tale.

What’s wrong with such a concept of God? It’s the beard! Seriously, the problem is that a guy who has a beard has parts and changing. Whether the parts are material or immaterial does not seem of very deep metaphysical significance. But having parts or changing, either one of these is an absurd anthropomorphism.

And hence I can’t get myself to believe in a God who changes or has parts. That leaves classical theism and atheism as the options. And atheism leads to scepticism, I think.

More on doing and allowing

Let’s suppose disease X if medically unchecked will kill 4.00% of the population, and there is one and only one intervention available: a costless vaccine that is 100% effective at preventing X but that kills 3.99% of those who take it. (This is, of course, a very different situation than the one we are in regarding COVID-19, where we have extremely safe vaccines.) Moreover, there is no correlation between those who would be killed by X and those who would be killed by the vaccine.

Assuming there are no other relevant consequences (e.g., people’s loss of faith in vaccines leading to lower vaccine uptake in other cases), a utilitarian calculation says that the vaccine should be used: instead of 316.0 million people dying, 315.2 million people would die, so 800,000 fewer people would die. That’s an enormous benefit.

But it’s not completely clear that this costless vaccine should be promoted. For the 315.2 million who would die from the vaccine would be killed by us (i.e., us humans). There is at least a case to be made that allowing 316.0 million deaths is preferable to causing 315.2 million. The Principle of Double Effect may justify the vaccination because the deaths are not intentional—they are neither ends nor means—but still one might think that there is a doing/allowing distinction that favors allowing the deaths.

I am not confident what to say in the above case. But suppose the numbers are even closer. Suppose that we have extremely precise predictions and they show that the hypothetical costless vaccine would kill exactly one less person than would be killed by X. In that case, I do feel a strong pull to thinking this vaccine should not be marketed. On the other hand, if the numbers are further apart, it becomes clearer to me that the vaccine is worth it. If the vaccine kills 2% of the population while X kills 4%, the vaccine seems worthwhile (assuming no other relevant consequences). In that case, wanting to keep our hands clean by refusing to vaccinate would result in 158 million more people dying. (That said, I doubt our medical establishment would allow a vaccine that kills 2% of the population even if the vaccine would result in 158 million fewer people dying. I think our medical establishment is excessively risk averse and disvalues medically-caused deaths above deaths from disease to a degree that is morally unjustified.)

From a first-person view, though, I lose my intuition that if the vaccine only kills one fewer person than the disease, then the vaccine should not be administered. Suppose I am biking and my bike is coasting down a smooth hill. I can let the bike continue to coast to the bottom of the hill, or I can turn off into a side path that has just appeared. Suddenly I acquire the following information: by the main path there will be a tiger that has a 4% chance of eating any cyclist passing by, while by the side path there will be a different tiger that has “only” a 3.99999999% chance of eating a cyclist. Clearly, I should turn to the side path, notwithstanding the fact that if the tiger on the side path eats me, it will have eaten me because of my free choice to turn, while if the tiger on the main path eats me, that’s just due to my bike’s inertia. Similarly, then, if the vaccine is truly costless (i.e., no inconvenience, no pain, etc.), and it decreases my chance of death from 4% to 3.99999999% (that’s roughly what a one-person difference worldwide translates to), I should go for it.

So, in the case where the vaccine kills only one fewer person than the disease would have killed, from a first-person view, I get the intuition that I should get the vaccine. From a third-person view, I get the intuition that the vaccine shouldn’t be promoted. Perhaps the two intuitions can be made to fit together: perhaps the costless vaccine that kills only one fewer person should not be promoted, but the facts should be made public and the vaccine should be made freely available (since it is costless) to anyone who asks for it.

This suggests an interesting distinction between first-person and third-person decision-making. The doing/allowing distinction, which favors evils not of our causing over evils of our causing even when the latter are non-intentional, seems more compelling in third-person cases. And one can transform third-person cases to be more like first-person through unencouraged informed consent perhaps.

(Of course, in practice, nothing is costless. And in a case where there is such a slight difference in danger as 4% vs. 3.99999999%, the costs are going to be the decisive factor. Even in my tiger case, if we construe it realistically, the effort and risk of making a turn on a hill will override the probabilistic benefits of facing the slightly less hungry tiger.)

Wednesday, April 21, 2021

Is it prudent to start drinking alcohol?

Here is an interesing exercise in decision theory.

Suppose (as is basically the case for me, if one doesn’t count chocolates with alcohol or the one or two spoonfuls of wine that my parents gave me as a kid to allay my curiosity) I am a man who never drunk alcohol. Should I?

Well, 6.8% of American males 12 and up suffer from alcoholism. And 83% of American males 12 and up report having drunk alcohol. It follows that the probability of developing alcoholism after drinking is around 8%, whle the probability of developing alcoholism without drinking is around 0%.

Family history might provide one with some reason to think that in one’s own case the statistics on developing would be more pessimistic or more optimistic, but let’s suppose that family history does not provide significant data one way or another.

So, the question is: are the benefits of drinks containing alcohol worth an 8% chance of alcoholism?

Alcoholism is a very serious side-effect. It damages people’s moral lives in significant ways, besides having serious physical health repercussions. The moral damage is actually more worrying to me than the physical health repercussions, both because of the direct harms to self and the indirect harms to others, but the physical health considerations are easier to quantify. Alcoholism reduces life expectancy by about 30%. Thus, developing alcoholism is like getting a 30% chance of instant death at a very young age. Hence, the physical badness of facing an 8% chance of developing alcoholism is like a young child’s facing a 2.4% chance of instant death.

At this point, I think, we can get some intuitions going. Imagine that a parent is trying to decide whether their child should have an operation that has about a 2.4% chance of death. There definitely are cases where it would be reasonable to go for such an operation. But here is one that is not. Suppose that the child has a condition that makes them unable to enjoy any food that has chocolate in it—the chocolate is harmless to them, but it renders the food containing it pleasureless. There is a childhood operation that can treat this condition, but about one in forty children who have the operation die on the operating table. It seems to me clear that parents should refuse this operation and doctors should not offer it, despite the fact that chocolate has great gustatory pleasures associated it. Indeed, I think it is unlikely that the medical profession would approve of the operation.

But I doubt that alcohol’s morally legitimate pleasures exceed those of chocolate.

I said that the moral ills of alcoholism are larger than the physical, but harder to quantify. Still, we can say something. If the physical badness of an 8% chance of alcoholism is like a young child’s facing a 2.4% chance of instant death, and there is a worse moral effect, it follows that the overall badness of an 8% chance of alcoholism is at least as bad as a young child’s facing a 5% chance of instant death. And with a one in twenty chance of death, there are very few operations we would be willing to have performed on a child or ourselves. The operation would have to correct a very dangerous or a seriously debilitating condition. And alcohol does neither.

This suggests to me that if the only information one has is that one is male, the risk of alcoholism is sufficient that the virtue of prudence favors not starting to drink. If one is female, the risk is smaller, but it still seems to me to be sufficiently large for prudence to favor not starting to drink.

There are limitations of the above argument. If one has already started drinking, one may have additional data that goes beyond the base rates of alcoholism—for instance, one may know that in twenty years of drinking, one has not had any serious problems with moderation, in which case the argument does not apply (but of course one might also have data that makes alcoholism a more likely outcome than at the base rate). Similarly, one might have data from family history showing that the danger of alcoholism is smaller than average or from one’s own personal history showing that one lacks the “addictive personality” (but in the latter case, one must beware of self-deceit).

I am a little suspicious of the above arguments because of the Church’s consistent message, clearly tied to Jesus’s own practice, that the drinking of alcohol is intrinsically permissible.

It may be that I am overly cautious in thinking which degree of risk prudence bids us to avoid. Perhaps one thing to say is that while there are serious reasons of prudence not to start drinking, I may be underestimating the weight of the benefits of drinking.

I also think the utilities were different in the past. If spices and chocolate are unavailable or prohibitively expensive, wine might be the main gustatory pleasure available to one, and so the loss of gustatory pleasure would be a more serious loss. Likewise, alcoholic drinks may have health benefits over unsafe drinking water. Finally, even now, one might live in a cultural setting where there are few venues for socialization other than over moderate alcoholic consumption.

Of course, in my own case there are also hedonic reasons not to drink alcoholic drinks: the stuff smells like a disinfectant.

Is it permissible to fix cognitive mistakes?

Suppose I observe some piece of evidence, attempt a Bayesian update of my credences, but make a mistake in my calculations and update incorrectly. Suppose that by luck, the resulting credences are consistent and satisfy the constraint that the only violations of regularity are entailed or contradicted by my evidence. Then I realize my mistake. What should I do?

The obvious answer is: go back and correct my mistake.

But notice that going back and correcting my mistake is itself a transition between probabilities that does not follow the Bayesian update rule, and hence a violation of the standard Bayesian update rule.

To think a bit more about this, let’s consider how this plays out on subjective and objective Bayesianisms. On subjective Bayesianism, consistency, the Bayesian update rule and perhaps the constraint that the only violations of regularity are entailed or contradicted by my evidence. My new “mistaken” credences would have been right had I started with other consistent and regular priors. So there is nothing about my new credences that makes them in themselves rationally worse than the ones that would have resulted had I done the calculation right. The only thing that went wrong was the non-Bayesian transition. And if I now correct the mistake, I will be committing the rational sin of non-Bayesian transition once again. I have no justification for that.

Moreover, the standard arguments for Bayesian update apply just as much now in my new “mistaken” state: if I go back and correct my mistake, I will be subject to a diachronic Dutch Book, etc.

So, I should just stick to my guns, wherever they now point.

This seems wrongheaded. It sure seems like I should go back and fix my mistake. This, I think, shows that there is something wrong with subjective Bayesianism.

What about objective Bayesianism? Objective Bayesianism adds to the consistency, update and (perhaps) regularity restrictions in subjective Bayesianism some constraints on the original priors. These constraints may be so strict that only one set of original priors counts as permissible or they may permissive enough to allow a range of original priors. Now note that the standard arguments for Bayesian update still apply. It looks, thus, like correcting my mistake will be adding a new rational sin to the books. And so it seems that the objective Bayesian also has to say that the mistake should not be fixed.

But this was too quick. For it might be that my new “mistaken” posteriors are such that given my evidential history they could not have arisen from any permissible set of original priors. If so, then it’s like my being in possession of stolen property—I have posteriors that I simply should not have—and a reasonable case can be made that I should go back and fix them. This fix will violate Bayesian update. And so we need to add an exception to the Bayesian update rules: it is permissible to engage in a non-Bayesian update in order to get to a permissible credential state, i.e., a credential state that could have arisen from a permissible set of priors given one’s evidential history. This exception seems clearly right. For imagine that you are the mythical Bayesian agent prior to having received any evidence—all you have are your original priors, and no evidence has yet shown up. Suddenly you realize that your credences violate the objective rules on what the priors should be. Clearly you should fix that.

Thus, the objective Bayesian does have some room for justifying a “fix mistakes” exception to the Bayesian update rule. That exception will still violate the standard arguments for Bayesian update, and so we will have to say something about what’s wrong with those arguments—perhaps the considerations they give, while having some force, do not override the need for one’s credences to be such that they could be backtracked to permissible original priors.

Considerations of mistakes gives us reasons to prefer objective Bayesianism to subjective Bayesianism. But the objective Bayesian is not quite home free. Consider first the strict variety where there is only one permissible set of original priors. We have good empirical reason to think that there are about as many sets of original priors as there are people on earth. And on the strict version of objective Bayesianism, at most one of these sets of original priors is permissible. Thus it’s overwhelmingly unlikely that my original priors are permissible. Simply fixing my last mistake is very unlikely to move me to a set of posteriors that are correct given the unique set of permissible original priors and my evidential history. So it’s a matter of compounding one rational sin—my mistake—with another, without fixing the underlying problem. Maybe I can have some hope that fixing the mistake gets me closer to having posteriors that backtrack to the unique permissible original priors. But this is not all that clear.

What about permissible objective Bayesianism? Well, now things depend on our confidence that our original priors were in fact permissible and that no priors that generate our new “mistaken” posteriors given our evidential history would have been permissible. If we have a high enough confidence in that, then we have some reason to fix the mistake. But given the obvious fact that human beings so often reason badly, it seems unlikely that my original priors were in fact permissible—if Bayesianism is objective, we should believe in the “original cognitive sin” of bad original priors. Perhaps, just as I speculated on strict objective Bayesianism, we have some reason to hope that our actual original priors were closer to permissible than any priors that would generate our new “mistaken” posteriors. Perhaps.

So every kind of Bayesian has some difficulties with what to do given a miscalculation. Objective Bayesians have some hope of having an answer, but only if they have some optimism in our actual original priors being not too far from permissibility.

It is interesting that the intuition that we should fix our “mistaken” posteriors leads to a rather “Catholic” view of things: although doubtless there is original cognitive sin in our original priors, these priors are sufficiently close to permissibility that cognitive repairs make rational sense. We have depravity of priors, but not total depravity.