Falling-block game in Minecraft

Over a recent trip, I had fun writing a little Python implementation of the classic falling-block game in Minecraft.

Our canine pets are animals, so we are animals

1. Our canine pets are primary bearers of their mental states.
2. Our canine pets are higher mammals.
3. So, some higher mammals are primary bearers of their mental states. (1 and 2)
4. Either (a) all higher mammals are primary bearers of their mental states or (b) no higher mammals are primary bearers of their mental states.
5. Human animals are higher mammals.
6. So, human animals are primary bearers of their mental states. (3, 4, 5)
7. We are primary bearers of our mental states.
8. If we are not human animals, then it is not both the case that we are primary bearers of our mental states and human animals are primary bearers of their mental states.
9. So, we are human animals. (6, 7, 8).

Premise 1 holds because the master-pet relationship to a canine pet while not being interpersonal (since dogs are not persons) has the kind of intimacy that requires the relata to be primary things with minds.

In correspondence, Jeff McMahan denied that our canine pets are animals. He held that our canine pets are not dogs but are rather constituted by dogs, much as he holds that we are not human animals but are rather constituted by human animals. So McMahan will deny premise 2. But I think premise 2 is obviously true.

The remaining controversial premise is 4, which holds that all higher mammals are on par with regard to whether they are primary bearers of their mental states. But I think 4 is highly plausible in light of the similarities between the brains and behavior of higher mammals.

I thank Allison Thornton for helping me work out this argument.

In vitro fertilization and creating genuine artificial intelligence

Catholic teaching says that there is (at least barring special divine dispensation) exactly one permissible way for human beings to directly produce new human beings: marital mating. This isn't just an arbitrary prohibition--arbitrary prohibitions like the one against pork went out (or, more precisely, underwent aufhebung) when the New Covenant came in. What is the reason for this restriction? We can, after all, permissibly produce other kinds of animals in other ways. There is no Catholic teaching against using artificial insemination in cattle.

I see two options. The first is that it is just the reflexiveness in human beings producing human beings requires the restriction. This seems implausible to me. Imagine that we meet Martians. It would be very odd to think that the Vulcans could permissibly produce new human beings in vitro and humans could permissibly produce new Vulcans in vitro, although humans couldn't permissibly produce humans in vitro (or Vulcans Vulcans).

The second option is that this has something to do with what is special about the target of production: a new human being. But what is it that is special about this target? It seems plausible that it is personhood. This suggests that we are only permitted to directly produce persons by marital mating. (Why? Maybe it has something to do with the more intimate way in which persons are images of God, and hence sacred, as in Paulo Juarez's comment. Or maybe there is a Kantian argument that other forms of production would fail to treat the persons as ends.)

But now if we were to generate genuine artificial intelligence--not merely computers acting as if they were intelligent--then we would have produced a person, and done so apart from marital mating. If I am right that it is personhood that is at the root of the prohibition on in vitro fertilization, it seems to follow that (at least barring special divine dispensation) it is impermissible for us to produce genuine artificial intelligence (AI).

Should this ethical constraint hamper AI research? That depends on whether there is significant reason to think that computers could ever actually have genuine intelligence. If dualism is true (and Catholicism entails dualism), then the only way a computer could gain genuine intelligence, as opposed to merely behaving like an intelligent thing, would be by gaining a soul. But perhaps God has enacted something like a law of nature by which whenever matter is organized in such a way that it could support intelligence, then that matter comes to be ensouled. If so, there could be an ethical problem in aiming at genuine artificial intelligence, and this could ethically restrict AI research since we might not know where the line of sufficient organization would be crossed (presumably, though, we're not that close to the line yet).

Maybe, though, things aren't so simple. Maybe rather than there being a general prohibition on our producing persons except by marital mating, what we have is a general prohibition on our directly producing persons by means other than the natural direct means for originating those kinds of persons. For humans, the natural direct means for origination is marital mating. But for intelligent computers, factory production could perhaps be the natural means for originating. Maybe, but I find more plausible the idea that we simply do not have the right to make persons, except by marital mating.

Reproductive ethics and divine intellectual property

God made everything. He did so timelessly eternally, and is fully responsible for everything that exists. He is not just a first cause, but an artist, author, designer and architect. It seems not unreasonable to suppose that during his eternal lifetime God has intellectual property rights to what he has made, including all biological forms of life. If so, then something like a license from God is needed to copy significant parts of creation.

A reasonable reading of Genesis tells us that God made us stewards of the non-human world around us, and in particular he has given us license to engage in agriculture, including the duplication of animals and plants. But we have not been given similarly far-reaching license with regard to humanity. We are told to be fruitful and multiply, but to be fruitful and multiply is not the same as to duplicate ourselves by any means possible. We have very good reason to think that we have license to use our reproductive organs to reproduce within a relationship designed for this purpose, namely marriage. But we have little reason to think that we have any license to reproduce outside of such a relation or that we have license to do so outside of the natural use of these reproductive organs. And the default assumption is that we have no permission to reproduce the intellectual property of another.

This line of thought generates something that is pretty much the Catholic picture of reproductive ethics. There is no permission for human reproduction outside of marriage. And reproduction needs to occur by means of human mating. Reproductive technologies, then, need to be limited to improving or repairing the reproductive potential of human mating, rather than replacing human mating by something else.

One can enhance the above story by noting that creatures have a two-fold connection with the divine artist. First, they are designed and created by him. Second, they are images of him. Some creatures are much more significantly divine self-portraits: these are persons, capable of interpersonal relationships of love. It is reasonable to think that there would be more significant restrictions on the copying of those works of art which are the divine self-portraits.

Objection 1: We shouldn't need to have Scripture to know that we may engage in agriculture and marital mating.

Response: Indeed. I think the relevant permissions are naturally "written in the heart". We intuitively grasp the difference between genetically enhancing wheat and genetically enhancing humans, and the difference between sperm banks for cattle and for humans. But the license to use new reproductive technologies is not so written in the heart.

Objection 2: Intellectual property rights are limited by society, which gets to define how long they last and to what degree they apply, and these rights are never endless.

Response: It is reasonable to think that there are such limitations for the property rights of human beings who themselves draw on centuries of culture for their creation. But God is a case apart.

Objection 3: Intellectual property rights are a matter of positive rather than natural law; they are created and modified by society.

Response: I share this intuition, and that makes me not want to full endorse the line of thought in this post. But perhaps we can say that intellectual property rights of humans are a very faint reflection of divine intellectual property rights, faint because all we have and create ultimately belongs to God, and also because of the dependence of our own creative work on that of others. So in us, it's a matter of social decision whether there be rights coming from our poor ways of creating. But God is fully and truly a creator.

Objection 4: This is too cold! God is the God of love, not an IP lawyer.

Response: The story is incomplete. But art isn't something cold, nor are the "moral rights" of artists something cold and for lawyers only.

What I am up to

My main philosophical project for the summer is cleaning up the draft of Infinity, Causation and Paradox. I've done the content cleanup in chapters 1-4 (bibliography is another thing) so far.

The elegance of fundamental physics

Plenty of the mathematics in science is ugly. But the mathematics in fundamental physics tends to be beautiful. It could be that in the correct fundamental physics it won't be beautiful. I wonder if we have reason to think it will be. The fact that in our current fundamental physics theories there is mathematical beauty doesn't seem to say much, because our current fundamental physics is probably false.

Still, I hope that the book of the world is written by God in such a way that the mathematical elegance of approximately true theories points to the mathematical elegance of the true theory in physics. I wonder, though, if an atheist could have any reason to have such a hope.

Free parameters in physics, ethics and epistemology

It looks like the laws of physics include "free parameters", constants that we feel could well have had other values than they do. It does not appear that these parameters can all be derived from more fundamental laws that have no free parameters.

Analogous phenomena occur in ethics. If to save your life, I must suffer a minor pain for a second, it is my duty to make the sacrifice. If to save your life, I must suffer constant torture for decades, it is not my duty to do so. As one increases the amount of my suffering to be weighed against your life, at some point one transitions from duty to supererogation (and perhaps eventually to just imprudence). Similar phenomena come up when deciding between goods to people with whom one has different relationships (saving n of one's cousins versus m strangers), when deciding between risks and certainties, etc. It does not appear that these parameters can all be derived from more fundamental laws that have no free parameters. (The best proposal for doing so is utilitarianism, and that just doesn't fit the moral data.)

And there are analogous phenomena in epistemology. For instance, there is the question of how quickly one should make inductive generalizations (in the Bayesian setting this comes to questions like: how high should be one's priors for generalizations).

In physics, the existence of free parameters is strong evidence for some sort of contingency in the laws. There are two ways to have such contingency. The first is to say that there could have instead been other laws. The second is an Aristotelian story on which the laws of physics are necessary but are conditional on the natures of things (e.g., if x is an electron, it behaves thus-and-so), and there could have been other things in the universe with other natures (e.g., shmelectrons instead of electrons) and then other laws--those with antecedents concerning the things with the other natures--would have been relevant.

The first approach raises a problem of explanation: Why are these the laws? The second approach reduces the explanatory question to a different explanatory question that we had anyway: Why are these the entities that exist?

In ethics and epistemology there are two options that can't be taken seriously in physics. One might, for instance, be a subjectivist of some stripe about the parameters (say, by being a subjectivist about all of ethics or epistemology, or just about the parameters). Or one might try to bring in vagueness to solve the problem--maybe it's vague at what point the needs of a larger number of strangers take precedence over a smaller number of cousins.

Vagueness does not, I think, solve the problem. For even if it's vague what the parameters are, it's not completely vague. It's non-vaguely true, for instance, that one should save a billion innocent strangers over one close relative. And subjectivism gives up too quickly.

It would be nice if one could give the same account of the free parameters problem in all three disciplines. Some accounts do not have much hope of doing that. For instance, one might solve the free parameters problem in physics by supposing that there is a multiverse with many different laws, either selected at random or with all possible laws exhibited, and it's just rock bottom that these laws are the laws where they are laws. The idea that there would be such variation in the moral or epistemological laws, with no explanation of the variation, is very unattractive.

There is a uniform Aristotelian story about all three free parameter problems. The parameters are necessarily what they are given the natures of the beings (physical beings, moral agents and epistemic agents) involved. The explanatory burden then shifts to the question of why these are the beings that exist. There is also a uniform divine choice story: God sets the parameters in the laws of physics, ethics and epistemology in a way that makes for a particularly good universe.

But there are, of course, non-uniform stories. One might, for instance, take the Aristotelian story about laws of physics, and a divine choice story about ethics and epistemology. But uniform stories are to be preferred.

Internet-enabled binary clock

I made my daughter an Internet-enabled binary clock with an ESP8266-12E unit. It should help her get familiar with binary. Here are build instructions.

Change and transition

It seems that necessarily:

1. If an object was F at t₁ and non-F at t₂, and the object existed at both of these times and all intermediate times, then the object changed with respect to F.

The at-at theory of change adds that this just is what change is, but in any case it seems quite uncontroversial that being F at one time but not another, while persisting from one time to the other, is sufficient for change.

But suppose that a lamp is on at all times that are rational numbers and is off at all times that are irrational numbers. Then according to (1), the lamp changed with respect to being on. Yet when did it change? A change is always a transition from one state to another. Suppose I take an ordinary lamp that's turned on at noon, off at 1, on at 2, and off again at 3. Then we can say that it changed from off before noon to on at noon; from on before 1 to off at 1, and so on. But there was no transition from on at noon to off at 3--there was, instead, a series of transitions. Likewise, then, if the lamp is on at t₁ (which then is rational) and off at t₂ (which is rational), it didn't transition from on at t₁ to off at at t₂. For after t₁ and yet before t₂, then lamp was off and then on and then off and so on, infinitely many times. So just as the ordinary lamp didn't transition from off at noon to on at 3, the weird lamp didn't transition from on at t₁ to off at t₂. Hence, it never transitioned.

What should we say? I guess we have three options. First, deny the possibility of a dense time sequence. Second, deny (1). Third, deny that change requires transitions.

Thomson's Lamp and change

Start with two Thomson's Lamps. They each have toggle switches and are on at 10 a.m. The switches are toggled at 10:30, 10:45, 10:52.5 and so on. Now suppose, as is surely possible, that regardless of what, if any, state the lamps would have had at 11 a.m., aliens come and instantaneously force the first lamp to be on at 11, and force the second to be off (say, by breaking the bulb!).

Now some but not all causal interactions are changes. Which lamp's on/off state did the aliens change? There are four possible answers:

1. The first but not the second
2. The second but not the first
3. Both
4. Neither.

Symmetry considerations rule (1) and (2) out of court. Can we say that in both cases, the aliens changed the on/off state of the lamp? Surely not. For if something can have only two states, it can't be that each of the two possible state inductions counts as a change. Moreover, if the lamp were to have changed state, what state did it change from? For inducing an on state only counts as a change if the induction starts with the lamp in an off state, and vice versa. But the induction didn't start with the lamp on, nor did it start with the lamp off. That leaves only last option: Neither.

But it seems that if an object has been persisting, and a causal interaction induced a state in that objection, that causal interaction either was a state-change or a state-maintenance. So if in neither case did the aliens change the state of the lamp, then it seems that in both cases they maintained the state. But we get analogues of (1)-(4), and analogues of the above arguments also lead to the conclusion that in neither case did the aliens maintain the state.

So the Thomson's Lamp story forces us to reject the dichotomy between state-change and state-maintenance.

Here's another curious thing. It seems that the following is true:

5. If an object has state A at t₁ and non-A at t₂, then the object's having state non-A at t₂ is the result of a change.

But applying (5) shows that both lamps' final states are the results of a change. But that change must have thus been from the opposite state. And yet the final state doesn't follow right after the opposite state.

One could use this as an argument against the possibility of infinitely subdivided time. Alternately, one could use this as an argument against principles like (5) and the idea that the concepts of change and maintenance are as widely applicable as we thought them to be.

IRToWebThingy

For quite some time, my older daughter has wanted me to make her Great Wolf Lodge Magiquest wand do something at home. So I made a simple IRToWebThingy (the link gives build instructions). It takes infrared signals in many different infrared remote controls and makes them available over WiFi. As a result, we can now watch Netflix with a laptop and a projector and the ceiling and play/pause with the Magiquest wand (and adjust volume with our DVD remote) with a pretty simple python script. My son (with some help) made a 3D etch-a-sketch script that lets him draw in Minecraft with the DVD remote. I made a fun script that lets you fly a pig in Minecraft with a Syma S107 helicopter remote (see photo). You can even control rooted Android devices with IR remotes and shell scripts.

Knowledge and scepticism

Some years back I learned that when epistemologists talk about the "problem of scepticism", they are thinking about theses that deny that we have much knowledge about, say, the external world. When I found out this, I was disappointed. I thought that the problem that epistemologists were dealing with was the problem whether we can be reasonable in believing things about the external world. I care about that, not about whether we know. Suppose it were to turn out that knowledge has to be infallible, and so indeed we know nothing empirical about the external world. This would hardly bother me. It's too bad that I couldn't say that I know that I have two hands, but my rational confidence that I have two hands would be just as high as it ever was.

We sell the scepticism at the beginning of Descartes' Meditations and throughout Sextus Empiricus far short if we think about it as simply a denial of knowledge. If we take seriously Descartes' invocation of the possibility of dreaming or of a deceitful demon, that not only has a tendency to undercut the claim that we know, but even the claim that we are rational in being confident in ordinary empirical beliefs, and maybe even the claim that it is rational to hold such beliefs to be more likely true than not. This is the more radical and more interesting scepticism: it questions whether we have any non-circular reason to think we aren't being deceived. (And in the end I think Descartes' answer to it is pretty good.)

The problem of induction in mathematics

Let's say I have some algorithm that generates the sequence of numbers, and I run ten iterations on the computer and get

• 1
• 1.5
• 1.41666666667
• 1.41421568627
• 1.41421356237
• 1.41421356237
• 1.41421356237
• 1.41421356237
• 1.41421356237
• 1.41421356237
• 1.41421356237

I will now be very confident that the sequence of numbers converges, and indeed that it converges to the square root of two. But why? Convergence is a property that the sequence has at infinity. The first 10 items in the sequence are an infinitely short proportion of infinity. Moreover, why do I assume that the sequence converges to the square root of two. Maybe it converges to the square root of two plus e⁻¹⁰⁰. Such possibilities ensure that my credence that the limiting value is the square root of two is strictly less than one. But the credence stays high.

In other words, the standard problems of induction come up not in just in science, but in mathematics. We should, thus, hope that whatever solutions we adopt to the problems as they come up in science will apply in the mathematical cases as well.

My favorite story about induction, the theistic story that God would have good reason--and hence be not unlikely to--create a well-ordered universe does not apply to mathematics, since pace Descartes, God doesn't choose the truths of mathematics. A relative of the story does apply, however. The truths of mathematics are grounded in the necessary nature of the mind of God, as Augustine held, and it is to be expected that the necessary nature of the mind of God will exhibit beauty and elegance. And where there is beauty and elegance, there is pattern and some purchase for induction.

Emotivism about art

Being largely tone-deaf, I don't appreciate music much at all. In fact, the older I get, the more music tends to annoy me, particularly when I meet it in the background of daily activities. I would much prefer listening to 4'33'' than to Mozart or Beethoven.

Yet I know that Mozart and Beethoven are much more beautiful music. Hence I embody a counterexample to emotivism about art. It is fun to be a counterexample (but I realize that it would be more fun to appreciate music, and I hope to do so in heaven).

Teaching programming with Python and Minecraft

Last summer, I taught programming to gifted kids with Python and Minecraft. Here's my Instructable giving a curriculum for a course like that.