A method for living forever

Maybe you have a cancer that would kill you in three months.

So, get a powerful rocket.

Accelerate close to the speed of light, and make a one light-year round-trip journey that from your reference frame takes about a month, but takes slightly over a year from the point of view of the earth. If your speed during the first journey was v₁, now repeat the same trip with a speed of v₂ = (3c²+v₁²)^1/2/2. Then repeat with a speed of v₃ = (3c²+v₂²)^1/2/2. And so on, forever.

Fact: Each journey will take a bit more than a year of earth-time but only half of the you-time of the previous. So the total you-time of your journeying will be 1 + 1/2 + 1/4 + 1/8 + ... = 2 months. You’ll never die. At every future time, you will be alive.

But this is pointless. You might as well stay on earth, and then you’ll have three months of you-time. Three months of you-time followed by death is better than two months of you-time with no death.

A Christian argument against eternalism, with some remarks on "finite" and "infinite"

1. We have an infinite future.

2. If eternalism is true, then anything that has an infinite future is infinite.

3. We are finite.

4. So, eternalism is not true.

The crucial premise is 2. One thought behind 2 is that our best version of eternalism holds that we four-dimensional, and if we have an infinite future, that makes us infinite in the fourth dimension.

But I think we can do better than that. Plausibly, part of what we mean by “We have an infinite future” is that we will have infinitely many token future mental states (if not, add that to the premises). On eternalism, all these mental states exist. And they are clearly all ours. So if we have an infinite future, we have an infinite mental life, and that is a way of being infinite.

I am an eternalist, and I want to affirm 1 and 3. What can I do? One move is this. The relevant sense of “finite” in 3 is not a mathematical sense, but something more “metaphysical” like limited. Now, to be limited is to have one or more limits. This is quite compatible with there being respects in which we lack a limit. Thus, the charged infinite rod that sometimes figures in physics homework has limits: not limits of length, but limits of width and height (and others). In the metaphysical sense, then, the rod is finite. Likewise, then, even if we are temporally infinite or infinite in the number of mental states, we are still limited in other ways.

If we go for this move, we have to make a choice what to mean by “infinite”. We could say that something is infinite provided there is some respect in which it is unlimited. If we did that, then one thing could be finite and infinite—as long as it is limited in one way and unlimited in another. The “infinite rod” would then be both finite and infinite. And, if eternalism is true and there is an eternal afterlife, we are finite and infinite. On this take, the argument is invalid, because it is missing the assumption that nothing is both finite and infinite.

A second otion is to make “infinite” mean unlimited in all respects. In that case, we are finite and not infinite. Indeed, only God is infinite then. A set with what the mathematician calls “infinite cardinality” is limited by not having a greater cardinality than the one it has.

A third option would be to take “finite” to mean limited in every way, “infinite” to mean unlimited in all respects, and then allow for the possibility of things that are neither finite or infinite—perhaps us.

Anti-Lucretian preferences

Lucretius famously argued that non-existence at the end of one’s life is no more to be feared than non-existence before the beginning of one’s life. Nagel famously argued that there is an asymmetry. One could exist later than one will but one couldn’t have existed earlier than one did. I think he’s barking up the wrong tree. Death wouldn’t be less scary if it turned out to be metaphysically inevitable.

But in any case, I think there is a way to prescind from the metaphysics questions. You’ve just woken up after an operation. You have amnesia. You expect the amnesia to wear off—somehow you have knowledge of how such things go. But for now you have it. You look through some files a careless actuary left lying about. You expect one of these files is about you. The files describe these cases:

• 35:20. Thirty-five-year-old expected to live twenty years more.

• 30:20. Thirty-year-old expected to live twenty years more.

• 20:30. Twenty-year-old expected to live thirty years more.

• 30:30. Thirty-year-old expected to live thirty years more.

• 20:20. Twenty-year-old expected to live twenty years more.

You can’t, of course, choose which of these is you, but you can have hopes and preferences. And suppose you think there is no afterlife.

My own preferences would be:

• 30 : 30 > 20 : 30 > 35 : 20 > 30 : 20 > 20 : 20.

I consistently have a preference for a longer future other things being equal, and a longer past other things being equal, but I tend to prefer a longer future to a longer past even if that results in a somewhat shorter overall life.

But only to a point. Suppose another file is:

• 50:28.

I definitely would greatly prefer that over 20:30, and not insignificantly over 30:30. The reason is that it seems quite a lot better to live 78 years than 50 or 60, even at the cost of two years of future life.

In any case, as regards my own preferences, Lucretius is just wrong. I would want more of a past life. Though to some degree my intuitions are distorted by the thought that in a longer life I am more likely to have more meaningful achievements.

What worries me philosophically about all this is whether I can reconcile my preferences with my belief in the B-theory of time. I think I can. It makes sense to me that the preferences I have at t should have a relationship to where t is located in my life.

Fear of death is not exactly fear of death or being dead

You don’t believe in the afterlife. Your doctor tells you that you will die in a week. You are terrified. A couple of minutes later, the doctor comes back, herself looking terrified. She tells you that she has both good news and bad news. The good news is that she had misdiagnosed you—you are just fine. However, the bad news is that her sister who is a cosmologist has just discovered that the everything—the universe, space and time—is coming to an end in a week. (She begs you not to tell anyone, because that will cause a panic.)

Out of nerdy curiosity, you ask the doctor whether there will be a last moment of time. She says that the same question occurred to her, and there won’t be. The interval of time is open on the upper end: for every time t, there is a later time t′. It’s just that time is literally running out, and all the remaining times are less than about a week from now.

With grim amusement you note that you won’t die. For at every time in the future you will be alive, and there won’t even be a last time which one might want to identify as the “time of death”.

You reflect. It’s a bit of a plus that none of your friends will suffer from your death, but a big minus that they all have only a week left. In any case, there is no relief from fear of death.

I think this case shows that it’s not death or being dead that we fear when we don’t believe in an afterlife. We fear the fact that our future is finite. If this is right, then people like Lucretius who thought that we somehow confusedly imagined ourselves as existing after the end of our existence and that this was what explained the fear of death are likely mistaken.

A nearly equivalent version of the above thought experiment would be one where you find out that you’re going to live for an infinite amount of time, but your life will exponentially slow down. In the next week of life, you will experience half a subjective week. In the week after that, you will only experience a quarter of a subjective week, and then an eighth and so on. Your subjective future will be a week. But you will never die. That’s just as bad as permanently dying.

A problem with perfectly rational agents and decision theory

Suppose I am perfectly rational in the decision theoretic sense. A coin is about to be tossed, and I will get five dollars on heads (H) and one dollar on tails (T). I have a choice whether to leave the coin fair (F) or load it (L) in favor of tails so that the probability of tails is 3/4.

It is obvious what I do. I calculate the expected utilities of my options F and L as follows.

• EU(F) = P(H|F) ⋅ $5 + P(T|F) ⋅ $1 = (1/2) ⋅ $5 + (1/2) ⋅ $1 = $3

and

• EU(L) = P(H|L) ⋅ $5 + P(T|L) ⋅ $1 = (1/4) ⋅ $5 + (3/4) ⋅ $1 = $2.

And then I choose F.

Except it’s not so simple. For I am perfectly rational. But since, as we just saw, the perfectly rational agent has to choose F, it follows that P(L) = 0, and so P(H|L) and P(T|L) are undefined. So I can’t decide! So now there is no guarantee how I will act, and P(H|L) and P(T|L) once again make sense. And then again they don’t. Oops!

What can be done? Causal decision theorists will note that I reasoned like an evidential decision theorist above. But this makes no difference in this case. The causalist’s story will be a bit more complicated but will end up with the same problem.

We might want to introduce primitive conditional probabilities like Popper functions that let you conditionalize on events with zero probability, and then have P(H|L) = 1/4 and P(T|L) = 3/4, even though P(L) = 0. But that is introducing a lot of complications. Primitive conditional probabilities are not unproblematic.

What should we do? Maybe we should suppose something like primitive suppositional decision theory, where what we are primitively given are the suppositional probabilities P^F and P^L, without them being defined in terms of conditional and unconditional credences as in evidential and causal decision theories. But this seems problematic. Do we have to suppose that in addition to conditional and unconditional credences, we have suppositional credences? Maybe.

Or perhaps decision theory only applies to agents that have non-zero credences of going for all the options.

An argument from wonderful people

1. Person x appears like they are in the image of God.

2. So, probably, x is in the image of God.

3. If God doesn’t exist, no one is in the image of God.

4. So, God exists.

From the imago Dei to God

1. It is not inappropriate to have a level of respect for human beings at least as great as what would be fitting for beings in the image and likeness of God.

2. If naturalism is true about humans and God does not exist, then it is inappropriate to have a level of respect for human being that is at least as great as what would be fitting for beings in the image and likeness of God.

3. So, either naturalism is false about humans or God exists (or both).

Regarding premise 1, think about how problematic it would be to say that someone like Mother Teresa had too much respect for her fellow human beings.

Regarding premise 2, naturalism tells us that innately we’re just an arrangement of atoms, and if we add to that that God doesn’t exist, then this arrangement of atoms doesn’t have a special God-directed significance, so it seems inappropriate to bestow on us the level of respect that a being in the image and likeness of God would have.

I think one can strengthen the argument to provide additional evidence for the existence of God. If God doesn’t exist, then the only plausible way that humans could deserve the imago Dei level of respect is if human beings have a deep and very valuable reality going far beyond the neural networks in our brains, a reality that intrinsically calls for that very high level of respect. (If there is a God, then we don’t need quite as much intrinsic value for us to be worthy of that kind of respect, because we could derive value from our relation to the infinite God.) This is much more than ordinary non-naturalisms about consciousness give.

We thus learn from considerations of respect that if there is no God, humans need to be very non-natural in a god-like way. And beings like that are very hard to explain apart from God. So if we are beings like, this provides significant evidence for theism.

A double lottery and non-normalized probabilities

Suppose a positive integer N is generated by a fair lottery.

Then, a random integer K is chosen between 1 and N (inclusive).

What information does this give you about N?

Obviously you now know that N ≥ K. Anything else?

Consider some specific pair of numbers n ≥ k, and suppose we’ve found out that K = k. What’s the probability that N = n? Of course P(N=n|K=k) = 0/0. But what if we do this as a limiting procedure. Suppose first that N is randomly chosen between 1 and M where M ≥ n, and let P_M be the probabilities for this case. Then

• P_M(N=n|K=k) = (1/M)(1/n)/[(1/M)Σ_j=k^Mj⁻¹] = (1/n)/Σ_j=k^Mj⁻¹.

Take the limit as M goes to infinity. Since Σ_n=k^∞j⁻¹ = ∞, the limit is zero, so we don’t have a meaningful distribution for N.

On the other hand, what if we independently choose two random integers K₁ and K₂ between 1 and N? Suppose n ≥ k_i for i = 1, 2. Let k^* = max (k₁,k₂). Then:

• PM(N=n|K1=k1,K2=k2) = (1/M)(1/n2)/[(1/M)Σj=k*Mj−2] = (1/n2)/Σj=k*Mj−2.

Take the limit as M → ∞ and call that P(N=n|K₁=k₁,K₂=k₂). The limit behaves like ck^*/n², for a constant c > 0, and generates a well-defined probability for N = n.

With zero samples, we don’t have a well-defined probability for N. With one sample, we still don’t. But with two samples (or more), now we do. This is a rummy thing: how is it that sampling turns probabilistic nonsense into sense?

This is making me more friendly to using non-normalized probabilities. After all, the fair lottery for N is easily modeled by the constant probability p₀(n) = 1. With one sample N = k, we have p₁(n) = 1/n for n ≥ k and p₁(n) = 0 for n < k. With two samples k₁, k₂, we have p₂(n) = 1/n² for n ≥ max (k₁,k₂) and p₂(n) otherwise. All this makes perfect sense. And there is a lovely mathematical feature of non-normalized probabilities: conditionalization is conjunction. The conditional probability of an event A on event B is just the probability of A ∩ B.

Non-normalized probabilities aren’t going to solve all problems with infinite fair lotteries. For instance, I toss a fair coin and generate a number N with the following rule. On heads, I choose N with my fair lottery on the positive integers. On tails, I choose N such that the probability of N = n is 2⁻ⁿ (e.g., I toss an independent fair coin and let N be the number of the first toss that gives heads). What’s my non-normalized probability p(x,n), where x is heads or tails and n is a positive integer? We surely want ∑_np(H,n) = ∑_np(T,n): the total probability of the heads options equals the total probability of the tails options. But clearly p(T,n) has to exponentially decrease so ∑_np(T,n) is finite and non-zero. On the other hand, p(H,n) is constant, so ∑_np(H,n) is zero or infinity. So they can’t be equal.

But I wonder if one could say something like this: Non-normalized probabilities make sense in certain cases, and in those cases it’s reasonable to use them?

Predictability and epistemic utility

You’re thinking whether to become an assembly-line worker or an artist. Then you reflect on the value of knowledge. And you become a factory worker, on the grounds that if you become an assembly-line worker, you will know what you’ll be doing every working day of your future, but if you’re an artist, your activities will be unpredictable.

Some remarks. First, there is something perverse about using the value of knowledge in this way. The normal way to pursue the value of knowledge is to find out things that are independent of your pursuit. But here you are pursuing knowledge by making there be less to know about the world (or your world). Yet, paradoxically, it sure seems like the line of thought above makes sense.

Second, the my initial story depends on Molinism being false. For if there are comprehensive subjective conditionals of free will, then by becoming an artist you get to know the conditionals about what you would do in the various artistic situations you’re in. But on the assembly line story, you don’t get to know these. So the Molinist doesn’t have the paradox. I suppose that’s a bit of evidence for Molinism.

Life-time epistemic utility

I’ve been thinking about the diachronic aspects of epistemic utility. In the case of non-epistemic utility, we can get a decent first approximation to life-time utility by adding up (or, if time is continuous, integrating) momentary utility. But I think this works less well for the epistemic case. For many things of purely epistemic importance, figuring them out is much more important than when one figures them out. (Granted, figuring them out earlier is instrumentally epistemically valuable, because it gives one more time to use leverage the knowledge to figure other things.)

Here’s an extreme version of encoding the value of “figuring something out”. Assuming one does not suffer from mental decline, the epistemic value of one’s life is the epistemic value of the very last moment of it. It’s interesting to note that this won’t work. For imagine that no matter what other credences you had at a given time, you always set the credence of “This is the last moment of my life” to one, while being careful to (inconsistently) make no use of this credence in update. If only the last moment counts, this modification to your credences would be a good idea: it makes sure that when the last moment comes, you get the epistemic utility credit for it.

I suspect that other weightings that favor later over earlier beliefs will suffer from a similar problem—they make it a good idea to err on the side of pessimism about how close death is.

But at the same time, I think some sort of favoring of later beliefs over earlier ones seems appropriate. I don’t know how to resolve this difficulty.

Gender/sex minimization and Christian sexual ethics

Here is a way to live a life: Generally strive to minimize the number of cases where one’s having a particular sex or gender functions as a reason for one’s actions or emotional attitudes.

An extreme version of this is not compatible with traditional Christian sexual ethics unless one is planning on celibacy. It is also not compatible with American law which requires one to correctly fill out various forms, such as census forms, that ask what one’s sex is. And it is not compatible with common-sense morality which requires one to respect things like sex- or gender-segregated bathrooms.

A moderate version of such a gender-minimizing practice, however, could be perhaps sustainable within the bounds of traditional Christian practice, American law and common-sense morality.

One might think that given the heterosexualism of traditional Christian practice, it is hard in romantic contexts to avoid basing decisions on reasons like “I’m a a man and she’s a woman.” In this post I want to explore the idea that one could instead base one’s romantic actions and attitudes on: “We are an opposite-sex pair.”

One might object: “That’s cheating. The reason why the two are an opposite-sex pair is that one is a man and the other is a woman.” But this is “reason” in a different sense of “reason” from that of reasons for actions and attitudes. That one is a man and the other is a woman is a metaphysical ground of the two being an opposite-sex pair, and it may well be one’s epistemic reason for thinking the two are an opposite-sex pair. But it need not be one’s reason for, say, asking the other out on a date—the reason for asking the other out on a date could just be “we are an opposite-sex pair”, and of course the delights of the other’s person, even if the evidence and metaphysical ground for “we are an opposite-sex pair” is the more fine-grained fact that one is a man and the other is a woman.

One could do the same thing when discerning a vocation to the priesthood. Instead of thinking “I’m a man, so I should consider the priesthood”, one might think “I am of the opposite sex to the symbolic sex of the Church (which in turn is the opposite sex to the sex of the incarnate Word), so I should consider the priesthood.”

Would formulating one’s reasons for action in such an unusual way have any benefits? I think so. “We are an opposite-sex pair” focuses one on a relation between the persons. On Trinitarian grounds, there is reason to think that relationality is central to personhood. Half of “I am a man and she is a woman” is self-focused. Better to use “we” than “I” in romantic thinking.

Moreover, we perhaps shouldn’t focus on what is morally irrelevant to a decision. Suppose two people are a good romantic match in terms of character traits, interests, etc., and one is male and the other is female. Supposing (perhaps per impossibile) that their sexes were swapped, but their character traits stayed the same, plausibly they would still be a good romantic match. That they are of the opposite sex is relevant romantically, assuming traditional Christian sexual ethics. But perhaps which one is a man and which one is a woman is not very relevant—what’s relevant is that the couple has one of each sex.

The picture in the above exploration is that the significance of men and women is largely relational: there is a relationship possible to a man and a woman that is not possible to two men or to two women. This is presumably because a man and a woman are an opposite-sex pair, or a potential mating pair, or something like that. This fact about a man and a woman is a relational fact. Granted, this relational fact is metaphysically grounded in certain biological features of the man and the woman, which features may not be themselves relational (say, the existence of body parts with a certain shape, or at least of activated genetic coding for them; though even there the teleology of the parts is relational). But even if the features are not themselves metaphysically relational, their ethical significance could still be largely relational.

Of course, in the end, the physical consummation of love in marital union will require each party to pay attention to the sexed nature of their own and the other’s bodies. That’s unavoidable. But perhaps that’s just a detail? I doubt it’s just a detail myself, but I could very well be wrong.

Another objection to the above story is that in love we focus on the specific features of the other, and in romantic love this includes sex-linked physical features. So when Juliet loves Romeo, she does not love him just as a “someone of the opposite-sex with character traits T₁, ..., T_n”, but also as someone with a rich set of lovely physical features, for which it is important that he is male, as many of them would be aesthetically and biologically unfitting in a woman. Agreed! But that doesn’t mean that Juliet’s own femaleness needs to be a part of her reasons for loving Romeo. Instead, she can love him as “someone of the opposite-sex to me with character traits T₁, ..., T_n, and with physical features Φ₁, ..., Φ_m which are splendidly fitted to his maleness.” Of course that Romeo is of the opposite-sex to Juliet and that Romeo is male implies that Juliet is female, but even though it implies this, it need not be a part of her reasons for love. I do like the thought that we should minimize focus on self in other-love.

Perhaps the above story isn’t right. I don’t endorse it. It’s entirely hypothetical. I find some features of the story attractive, but my credence in the story is well below 50%. There may well be ethically significant non-relational features of being and being female. Perhaps swapping the sexes of a well-matched romantic couple might in fact change whether they are a good match.

For instance, maybe there are specifically male virtues and specifically female virtues, and then swapping sexes while keeping character the same produces someone who lacks virtues that they should have. Maybe, but I am inclined to be skeptical of this suggestion. A more moderate view would be C. S. Lewis’s, that although men and women should have the same virtues, the lack of certain virtues in a man is worse than their lack in a woman and vice versa. That has more of a chance of being right. I could imagine future scientific research telling us that the typical hormonal make-up of men tends to make some virtues easier for them and the typical hormonal make-up of women tends to make other virtues easier for them. Lacking an easier virtue seems worse than lacking a harder virtue, other things being equal. If so, then if you swapped sexes while keeping characters unchanegd, the moral evaluation could change. Perhaps Alice and Bob are respectively a decent woman and a decent man, but Alice would make a terrible woman and Bob would make a terrible man. Maybe. But if they both got worse symmetrically in this way, while keeping the same actual virtues, maybe it wouldn’t make a big difference to their romantic relationships. They’d still have the same virtues between the two of them, the same vices between the two of them, it’s just that the evaluation of these virtues and vices would be a bit different. And in any case on a story like the hormonal one, it’s not clear that the specific sexes matter except causally, as tending to produce the hormones.

My thinking on this was sparked by two things. First, for a while I’ve been exploring imagining what life would be like if we were isogamous heterothallic organisms, which of course we are not. Second, I recently attended the defense of a very interesting dissertation arguing among other things that it is compatible with Catholic orthodoxy to hold that gender (though not biological sex) distinctions are a major result of original sin.

Epistemic utilities and death

In the previous post, I proved that we get a proper scoring rule if we compute epistemic utilities as follows. We start with our current credence assignment, consider what credence assignment we will have in the future after we update on some further evidence, and then score that. I then suggested that one could get a lifetime epistemic utility by adding up the epistemic utilities over all the moments of life, and as long as death wasn’t random—as long as the lifespan was fixed—this would generate a proper scoring rule. I then said that if death is random (as it is) it might be the case that you don’t get a proper scoring rule.

My conjecture was wrong. You still get a proper scoring rule despite random death. It’s easy to see this. The basic idea is this. Suppose that you might die the next moment. This partitions the probability space into two subsets, D and L, for death and life. Your current credence is p. Next moment, on D, your credence either doesn’t exist (because you don’t exist or you exist in some supernatural state where you don’t have credences) or doesn’t count (because I am after lifetime credences). Thus, the appropriate way to do a forward-looking scoring of your credence p is to score it s(p_L) on L and 0 on D, where p_L is the result of conditionalizing your credence on the evidence L (after all, if you are alive, you will conditionalize on being alive), and s is some proper scoring rule. In other words, your forward looking score is s_L(p) = 1_L ⋅ s(p_L).

Is this score proper? Yes! For by propriety of s we have:

• E_pL(s(p_L)) ≥ E_pL(s(q_L)).

But this is the same as:

• (p(L))⁻¹E_p(1_L⋅s(p_L)) ≥ (p(L))⁻¹E_p(1_L⋅s(q_L)).

Multiplying both sides by p(L) (I am assuming a non-zero probability of survival), we get:

• E_p(s_L(p)) ≥ E_p(s_L(q)).

We can combine this with a more complex set of future investigations as in the previous post, and things will still work.

It is crucial to the above argument that when you’re alive, you can tell you’re alive. I suppose that’s not always true. When you’re asleep, you are alive, but can’t tell you’re alive. So to generalize beyond the above toy example, replace death with unconsciousness or something like that.

Forward-looking scoring rules

An accuracy scoring rule assigns a score to a probability function representing an agent’s credences, ostensibly measuring how close that probability function is to the truth. The score s(p) of a probability function p is a random variable, because the value of the score depends on what is actually true, i.e., on where we are in the probability space.

A proper scoring rule (on probabilistic credences) satisfies the propriety inequality

1. E_ps(p) ≥ E_ps(q)

which says that the expected score of your current lights—your current credences p—by your current lights is optimal: you won’t improve your expected score (by your current lights) by switching to a different credence q.

You can think of a proper scoring rule as representing the epistemic utility of having a credence p.

But now let’s think about things dynamically. In the future, you will receive additional evidence. As a good Bayesian agent, you will update on this evidence by conditionalization. Perhaps instead of thinking about maximizing your current score, you should think about maximizing your future score. Maybe your true epistemic utility is the score you will end up with after all the future evidence is in.

A simple model of this is as follows. There is some finite partition I = (I₁,...,I_n) of your probability space Ω with each cell I_i of the partition representing a possibility for what you might learn given future evidence. Your current credence function is p, and p(I_i) > 0 for all i. There is then a random credence function p_I where p_I(ω) is the credence function you will have once the evidene is in if you are at ω ∈ Ω. In other words, p_I(ω)(A) = p(A∣I_i) where I_i is the member of the partition that contains ω. (Technically, the function that maps ω to p_I(ω)(A) is equal to the conditional probability p(A∣G) where G is the algebra generated by I.)

Now, given a proper scoring rule s, define a new scoring rule s_I as follows:

2. s_I(p)(ω) = s(p_I(ω))(ω).

Your s_I-score for p at ω then represents the score you will have at ω once you learn which cell of the partition I you are in.

Theorem: The scoring rule s_I is proper if s is proper.

Note that s_I won’t be strictly proper (i.e., (1) won’t always have strict inequality when p and q are distinct) if I has two or more cells, because p_I and q_I are going to be the same if p and q assign different probabilities to the cells, but have the same conditional probabilities on each cell. But it might still be the case that s_I is strictly proper with respect to some relevant subfield of Ω—that needs some further investigation.

Suppose now you are a Bayesian agent who is guaranteed to consciously live for n moments. In each moment, new information comes in. Thus, we have a sequence J₀, ..., J_n of finer and finer partitions, with J₀ being the trivial partition, and with p_Jk representing the credence you will have at time k. Your overall epistemic lifetime score is then:

3. s_Σ(p) = ∑_ks_Jk(p).

It follows from the Theorem that s_Σ is a proper scoring rule if s is. And if J₀ is the trivial partition, then s_J0 = s, and so if s is strictly proper, then the lifetime score s_Σ is strictly proper, since the sum of a strictly proper rule and a proper rule is strictly proper. So, lifetime scores are strictly proper if they are constructed from an instantaneous score—in the above toy model.

Alas, the toy model is not fully adequate, because it is random when we will die, and so our lifespan doesn’t have a fixed sequence of moments. Once we take into account the randomness of when we will die, the overall epistemic lifetime score might stop being proper: this needs further investigation.

Proof of Theorem: By the Greaves and Wallace Theorem, an optimal method of updating credences with respect to expected proper score is by Bayesian conditionalization. Apply the Greaves and Wallace Theorem to the scoring rule s and the starting credence p with the following two strategies:

A. Bayesian conditionalization on the true cell of I.

B. Switch your credence from p to q, then apply Bayesian conditionalization on the true cell of I.

Saying that (A) is at least as good as (B) is equivalent to the the proper scoring rule inequality (1) for s_I.

Aristotle on sexual reproduction

Infamously, Aristotle thought that in animal reproduction (including the human case) the male contributed form and the female the matter.

I think it would have made for a neater metaphysics if he thought it was the other way around. For his story involves the complication that there are three ways that a form of an animal exists:

1. as informing a piece of matter and making it an animal of the relevant type

2. as being transmitted by semen, without turning the semen into an animal of the relevant type

3. as being found abstracted in an intellect thinking about the animal.

But if he supposed instead that the form was contributed by the female, he could have said that the semen contributes a small packet of initial matter for the organism and the female’s form works upon that packet in utero. At no point in this process is there a form that is separated out from an organism with that form (such a case will still have to happen when an intellect abstracts that form from matter), and so case (b) disappears, along with all the consequent metaphysical complications to the system.

It’s not clear to me how exactly Aristotle handled this. In Generation of Animals, he talks of the “power of the male residing in the semen”. This sounds like a kind of virtual presence of the form of the animal, a presence of the form as implicit in a causal power. It would be nice to be able to skip this complication. (Granted, Aristotle would still have a similar problem with regard to his view of delayed ensoulment, on which the offspring of a human is first a kind of plant, then gains an animal form, and then gains a rational form, for then the plant has a power to make an animal and the animal a human.)

I guess one might try to find Aristotle a way of reducing (b) to (a) while making the male still be the contributor of form as follows. One might think the semen is a living part of the male’s body, metaphysically like other parts, but separated spatially from the rest of the body (given what we know about how we are made of molecules, it is clear that spatial separation cannot be a bar to bodily unity). Thus, the semen would still be informed by the father’s form, in exactly the same way that the father’s ear or heart is. But this would have a downside. Suppose the father apparently died while the semen continued living, as does happen. Then it seems that the father would not have actually died—instead, his body would be reduced to a packet of semen, and he will have literally gone to seed. This seems absurd.

Why did Aristotle not go for the female as source of form solution, which is so neat metaphysically? Maybe for two reasons. First, the semen obviously could only contribute very little matter. (But then why not suppose that the initial organism is very small?) Second, sexism.

A really big choice

A messy Irenaean world which leaves much to be desired and then grows in value due to our contribution has a great value.

A perfectionistic world where everyone is already perfectly virtuous and everything is good and we just maintain that level of good also has great value.

Quite plausibly the two worlds have incommensurable value.

God could just choose between these incommensurable values. But what God does is something else: he leaves it to the first humans to choose. This seems an especially great gift: we get to choose the basic shape of the value that our world takes.

We sin, and we get the Irenaean world.