Friday, July 29, 2016

Presentism, open future and spoken sentences


  1. Both presentism and open future are true,
a not uncommon combination. Next, plausibly:
  1. It is an essential feature of a sentence token that it has the number of words it does.
Suppose I am now saying a sentence, and have so far uttered the four words "The sky is blue". Let S be my sentence token. Then:
  1. There is no fact whether the sentence I am now saying is four words long.
For whether it is four words long depends on what I will go on to say, and that depends on my free will, and so by open future, there is no fact about it. But
  1. It is a fact that the sentence I am now saying is S.
  1. There is no fact whether S is four words long.
But necessities are never open, and what essential features an object has (if it exists) is a matter of necessity. Hence (5) contradicts (2).

There is a host of premises one can use in place of (2). For instance, it seems to be an essential feature of a spoken sentence token that it ends with a particular sound, or that it has such-and-such grammatical form in such-and-such a language.

Thursday, July 28, 2016

Of balloons and transubstantiation

Our three-dimensional space is curved, say, like the surface of a balloon--except that the surface of a balloon is two-dimensional while space is three-dimensional.

Now imagine you have an inflated balloon. Draw two circles, an inch in diameter, on opposite sides, one red and one blue. Put your left thumb in the middle of the red circle and your right thumb in the middle of the blue circle. Press the thumbs towards each other, until they meet, with two layers of rubber between them. The balloon now looks kind of like a donut, but with no hole all the way through. Imagine now that you press so hard that the two layers of rubber between your thumbs coalesce into a single layer of rubber.

Now the single layer of rubber between your thumbs is at the center of the red circle and at the center of the blue circle. We can think of each circle as defining a place, and the coalesced rubber inside it is found in both of these places.

Replace the red circle with a drawing of a church and the blue circle with a drawing of heaven. The same coalesced layer of rubber is both inside (a drawing of) a church and inside (a drawing of) heaven. Suppose now that the rubber is infinitely thin, and that there is a space that coincides with this rubber, and little two-dimensional people, animals, plants and other objects inhabiting this space, much as in Abbott’s novel Flatland . Suppose that the pictures of the church and heaven are replaced with two-dimensional realities. Then the space of the church and the space of heaven literally overlap, so that there is a place that is located in both. An object found in that place will be literally and physically located both in the church and in heaven. In one sense, that object is physically located in two places at once. In another sense, it is located in a single place, but that single place is simultaneously located both in heaven and in the church.

There is no serious additional conceptual difficulty in three-dimensional space curving in on itself similarly.

(This is largely taken from a forthcoming piece by Beckwith and Pruss.)

Tuesday, July 26, 2016

If the future is open, it is never true that one is saying the truth

Given an open future, it is only true once one has already spoken that one says/said a particular sentence. For as long as one is still speaking, there is no fact of matter about how the sentence will end. It might end in an emphatic "--not!" So no utterance is true while it is being made. It can only be true after a decent pause. This is implausible, so we should reject the open future.

Monday, July 25, 2016

Plagiarism and a repeat invitation

I am occasionally asked whether I am not afraid that someone will steal ideas from my blog and publish them. I'm not. If the ideas get published by someone else, that saves me the trouble of writing them up myself. Hopefully they will give credit where credit is due and it won't be theft.

Moreover, I invite anybody competent who wants to coauthor a paper with me by starting with the ideas in a post, working out the details and writing up a first draft. (Check with me first before getting to work, though.) In the philosophical profession, coauthored papers count pretty much the same as single-authored, so plagiarizing would involve unnecessary risk for very minor benefit.

Sunday, July 24, 2016

Virtual parts, compressed files and divine ideas

Suppose I record some video to a file on my phone. The video on my phone then is made up of frames, say, 30 of them per second. The frames are parts of the video that it sure seems like we can quantify over. But what is a frame of the video? Well, it's natural to say: The file consists of a sequence of bits implemented as flash memory states arranged spatially in the flash memory of the phone (though not always in the "logical" order, because of wear-leveling and filesystem issues). A frame then would seem to be a subsequence of these flash memory states. But that is in general false. Video files are typically compressed. While some frames--the "key frames"--are stored as a whole as a discrete sequence of bits, typical frames are not stored as a whole. Instead, what is stored is basically a set of instructions on how to modify one or more other frames in order to get the current frame. For instance, if you are panning smoothly across a static object from left to right, the non-key frames will presumably say something like: "Take most of the previous frame, shift it over a little, and then add such and such pixels on the right." But we cannot identify the bits of an instruction like that with the video frame itself, because the video frame does not supervene on the instruction: it supervenes on the instruction and the previous frame.

Even a liberal materialist ontology with unrestricted composition that allows for fusions of arbitrary disconnected sequences of bit-encoding states, the parts of the video do not exist. Noentheless, we correctly (and truthfully) say in ordinary language that the video is made up of frames as parts.

This is a rather nice illustration, I think, of the Thomistic concept of virtual parts. Virtual parts are not fundamental ingredients in the ontology. Nonetheless it is correct (and truthful) to talk of them in ordinary language. There are other such illustrations in computing. For instance, images and sounds are compressed by algorithms that transform them from spatial or temporal sequential data to frequency data or wavelet coefficients. The "natural" parts of the image or sound (say, "the left half", or "the last third") will typically not correspond to a physical part of the device memory storage.

A more homely example is, I am pretty sure, the human visual system. I see an image composed of a variety of parts. There is a lit-up rectangular part (the laptop screen), which has a left half and a right half, and so on. But even without looking up any brain research, I am willing to bet quite a lot that the disjoint spatial parts of the visual image do not correspond to particular things in my brain: I do not have an array of pixels in the brain whose parts correspond to the parts of the image (I do not even have an array of pixels in the retina corresponding to the parts of the image, as the image is stitched together by the brain over time from a variety of images produced by eyes that are constantly moving across the image).

(Can the Platonist avoid talking of virtual parts, insisting that videos and pictures are abstract objects? But even if videos and pictures are abstract objects, I doubt that they have frames and subpictures as parts.)

One thing I would like to use this story for is divine ideas. God is fundamentally simple. But we can meaningfully and truthfully talk of a multiplicity of divine ideas, in much the way that we can talk of the parts of the visual image, which are all encoded in God's one idea of all possibility. And this grounds worlds, propositions and the like.

Friday, July 22, 2016

Four-dimensionalism and interpersonal connections

I have thought about reality as four-dimensional since I was ten years old. Yesterday morning I was sitting in a conference room, and I decided to imagine what it would be like to think of the people there as if presentism were true and they were all merely three-dimensional. I then saw the people as small, disconnected lone individuals. I've since been reflecting on the way that four-dimensionalism can change how we see people.

If four-dimensionalism is true, we are four-dimensional stalks, branching off from our mothers, with a slightly less direct connection to our fathers. Together we all form an interwoven mat of upward growing stalks, stalks in contact where we, say, shook hands, hugged, kissed or even fought. The picture is no longer one of lone individuals, but of a complex multiply interconnected system. It's like a family tree where the branches are all twisted around each other.

Of course, the presentist will say that it is true that we came from our mothers, that we were begotten by our fathers, that we shook hands, hugged, kissed or fought, and so on. But on presentism these connections are past, over and done with. We are basically lone individuals, who at a variety of past times came in a variety of contacts. It is the four-dimensionalist who has a metaphysics that captures the fact that no one of us is an island.

Thursday, July 21, 2016

An open future precludes present motion

  1. Whether an arrow is moving now depends on where it will be in the future.
  2. If the future is open, there is no fact about where the arrow will be in the future.
  3. If if whether p depends on how A is, and there is no fact about how A is, then it is not a fact that p.
  4. So, if the future is open, no arrow is moving now.

Premise 1 is the most controversial one. Suppose that an arrow has been flying for half a second. There are two metaphysically possible worlds. In the first, it continues moving as usual. In the second, its motion instantly reverses after this moment, so that this moment is the furthest point in its flight. In the second world there is no more reason to say that the present moment is the last moment of forward motion than to say that it is the first moment of backward motion. So we shouldn't say the arrow is moving forward in the second world.

Hence there are worlds that differ on whether the arrow moves now and yet that differ only in the future positions of the arrow. That gives us reason to accept 1.

Premise 2 is particularly clear given theism: God can miraculously relocate the arrow if he so chooses. But I think premise 2 is going to be plausible on other views, too.

Divine aseity and light-weight Platonism

Here's a standard theistic argument against Platonism: If Platonism is true, then God is dependent on properties like divinity, goodness, omniscience and omnipotence. But God is not dependent on anything. So, Platonism is false.

I think it's worth noting that this argument only works given heavy-weight Platonism. The light- and heavy-weight Platonists agree that, at least if F is fundamental, x is F if and only if x instantiates Fness. But the heavy-weight Platonist adds the claim that if x is F, it is F because it instantiates Fness. The light-weight Platonist--van Inwagen is the most prominent example--makes no such explanatory claim.

Without the explanatory claim, the dependence argument for a conflict between Platonism and theism fails. For while it may be true on light-weight Platonism (assuming "is divine" is fundamental--something that Jon Jacobs at least will deny--or an abundant Platonism) that God is divine if and only if God instantiates divinity, we cannot conclude that God's being divine depends on God's instantiating divinity or on any other property. Indeed, the light-weight Platonist could (but does not have to) even make the opposite claim, that God instantiates divinity (or goodness, omniscience and omnipotence) because he is divine (and good, omniscient and omnipotent).

Of course, the aseity argument isn't the only reason to deny Platonism. God is the creator of everything other than himself, and that causes problems for properties, too.

Wednesday, July 20, 2016

From causal finitism to divine simplicity

If God is not simple, he has infinitely many really distinct features. Moreover infinitely many of these features will be involved in creation, e.g., because there are infinitely many reasons that favor the creation of this world, and for each reason God will plausibly have a distinct feature of being impressed by that reason. But causal finitism (the doctrine that infinitely many things can't come together causally) rules this out. So divine simplicity is true.

Assuming causal finitism, the thing that one might challenge is the claim that infinitely many of God's features are causally efficacious.

There is an even easier argument for divine simplicity based if actual infinites are impossible. For, surely, either (a) God is simple or (b) God has infinitely many really distinct features. If actual infinites are impossible, that rules out (b).

Tuesday, July 19, 2016

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.

Monday, July 18, 2016

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.

Saturday, July 16, 2016

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.

Friday, July 15, 2016

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.

Friday, July 8, 2016

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.

Wednesday, July 6, 2016

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.

Monday, July 4, 2016

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.

Friday, July 1, 2016

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.