Where time becomes a loop, where times becomes a loop, …

As I mentioned last week, I'm reading From Eternity to Here by Sean Carroll. It's a physics book for laypeople and is about time.

Time is a funny thing when you stop to think about it. What exactly is it? How do you define it in non-temporal terms? That isn't easy to do, and you won't be getting any answers here. If I thought I was out of my league while reading medieval monotheistic philosophy, then I feel doubly so now, reading about general relativity and spacetime curvatures. But I like the book a lot. I'm not taking notes—just reading through and absorbing whatever happens to soak in.

Physicists sometimes talk about time as a fourth dimension, but time doesn't appear (at first glance) to have the same symmetries as the other three dimensions. As Sean Carroll puts it, you can turn whichever way in 3D space and maybe even get lost, but you can't make a wrong turn into yesterday. That is, time always runs forward—at least as we perceive it. Why? That's a big question the book aims to answer. At the heart is the idea of entropy and how the quantity of information in the universe has steadily increased ever since some initial high-order state, which we call the Big Bang.

A lot of people wonder where order comes from, even to the point where it affects science's credibility, such as when someone professes their skepticism that complex life could self-arrange from simpler components. The question where does order come from? is interesting, but there's a good answer for it: order comes about by making some other place even less orderly. In that sense, order isn't any more mysterious than the cold air blowing out of an air conditioner. Where does refrigerated air come from on a hot summer day? Answer: by pumping heat uphill to the outdoors—i.e., making some other place even hotter. Marvelous, yes, but straightforward nevertheless.

But the where does order come from? question leads to a compliment question that's harder to answer: where does disorder come from? Currently, no one knows. Not all disorder comes about as a result of order increasing somewhere else. Disorder is, on average, increasing in the universe, so some disorder is coming about from—well, no one knows. Whatever the answer, it appears to have something to do with the essence of time itself.

Time travel

You can't write a physics book about time for laypeople and not include a chapter about time travel, and this book dutifully has one. In it Carroll discusses qualitative features of various theoretical ideas about time travel. One idea is the closed loop of time, called a closed timelike curve in the book. A closed timelike curve is spacetime that bends enough to form a circle, thus causing events to cycle repeatedly, like in this episode of Star Trek TNG.

I'm going to spoil the plot: it appears unlikely that it's possible to create a closed timelike curve if the universe isn't set up from the get-go to produce one. This has to do with the enormous amount of energy required to bend spacetime into a circle. Nevertheless, such loops are interesting to think about as thought experiments. In particular, they necessitate what seems to us to be a problem: a choice between paradox or defying entropy's relentless march.

To explain this, Carroll uses an example of a gate that leads into yesterday. That is, if you walk through the gate at 3PM on Wednesday, you will emerge on the other side at 3PM on Tuesday. Other than this fact, there's nothing weird about the gate—no strange force field, no Hollywood-style light show. You walk through it like any ordinary gate. Someone watching you from the Wednesday side would see you pass through normally, though on the other side you would be in Tuesday. (The observer would be looking backwards in time when they see you on the other side.)

Once in Tuesday, you would walk around as though it were any other ordinary day and re-experience the previous twenty-four hours, but at the end of that time you would return to the Wednesday side of the gate and pass through again. That is the meaning of a closed loop. The paradox problem stems from the notion of freewill: what if you chose not return to the gate? What if you instead decided to board a plane headed to another continent or to shoot yourself in the head? The idea of a closed loop of ever repeating events conflicts with our sense of freewill.

We may resolve the paradox by hypothesizing there's no freewill. But without freewill we're presented with another problem: entropy. After passing through the gate, you spend the next twenty-four hours walking around, doing whatever it is you did previously, and then return to the Wednesday side the gate. However, the condition in which you return to the gate must be exactly the same as the condition you were in when you last passed through the gate. Your hair must be the same, the specks of dust and dirt on your pants must be the same. Every cell and every atom in you must be exactly the same. You must not have aged, learned anything, forgotten anything, or changed in anyway. But this sort of thing just doesn't happen over the course of any twenty-four hour period. Things wind down, and they become more disorderly. A closed timelike curve defies this.

As I said, you won't be getting any answers here.

What happened, dear Astros?

Yesterday I found out the Astros will move to the American League after this coming season. Upon hearing the news, my first impulse was to resign as an Astros fan. But such an overly dramatic and potentially regrettable decision is worthy only of Mets fans, and I know as plain as any fact that in baseball one doesn't give up on one's home team on one bit of bad news alone. Rather, one first waits a few years, enduring bad trades and losing seasons؟

But moving to the Devil League is the worst possible news. To put this in perspective, even if the Astros were to lose all 162 games in a season I would think to myself, Well, at least the Astros played baseball, not like those imposters in the AL, who don't make everyone hit. In baseball, every player hits. Every player hits. I looked at the Astros' presence in the NL and the Rangers' presence in the AL as tangible proof that Dallas is an inferior city to Houston. Now they're division rivals., and I'm forced to rethink my conclusions.

Though, the core of my problem isn't so much with the Astros as it is with MLB. Don't misunderstand me: I fully expect any professional sport to whore itself out given the chance—kudos to anyone who figures out how to earn good money through recreation. But MLB continues to degrade itself from its former position as a high-class call girl to that of a common street hooker on dollar day. Baseball has always been idiosyncratic and resistant to change, but now it seems regretful about it, reforming itself slowly enough to hope no one notices. Well, I notice.

First they created the DH as a kind of pre-retirement package for aging players—a change that appeals to the kind of fan who conflates hitting home runs with strategy. Then they devised interleague play, which eliminated the mystique of the NL-AL distinction and the privilege of the World Series. Then there was the steroid era and MLB's complicity in trashing sacred records to win back fans from the 1994 strike. Now, using the Astros' league switch as an excuse, MLB is increasing the prevalence of interleague play.

I say MLB should stop beating around the bush and just openly mimic the NFL. Here's an idea. Even in pro baseball, not all players excel at both offense and defense. How about splitting each team into two squads of specialists, one for offense and one for defense? Batter shows bunt? Bring in the special team to handle that.

</rant>

Grammar Gripe Tuesday

Three words rarely used correctly and meaningfully are: clearly, obviously, and literally. Though these words have their appropriate uses, they've become so misused in modern English that they should raise a red flag each time you write them.

Clearly & obviously

Clearly and obviously both suffer from the same common misuse, which is that as a meaningless transition between two ideas. Take the following example:

X and Y are large values. Clearly, we don't have enough time to compute Ackermann's function with X and Y as its inputs.

Such use of clearly is self-defeating. If the reader happens not to know about Ackermann's function, then clearly is flat wrong; it's not clear. But if the reader does know about Ackermann's function, then you don't need to alert them to the clarity of the statement. If the statement is clear, they'll know. In any event, it's bad form to point out the obvious.

Obviously, X is greater than Y.

If it were obvious that X is greater than Y, then hopefully you'd have the sense not to write it. Maybe the word you're looking for is thus or therefore.

Literally

The average person probably has a good reason to use the word literally no more than four or five times a year. Literally shouldn't be a common word, but somehow it is, having taken on a new meaning as a kind of superlative—as when mere figurative speech won't do.

On our camping trip the mosquitoes literally ate us alive.

Wow! Man-eating mosquitoes! A zombie that can write! Forget whatever point the author was trying to make; I want to know more about what it's like to be reanimated.

The correct use of literally is when you intend to be taken non-figuratively while using a phrase that's commonly a figure of speech. For example:

George literally worried himself sick over his midterm exams.

We know George is not merely anxious about the exams; he's actually sick, and probably puking is involved.

These gripes may seem small, but they're part of communicating well. These days, anyone reading your words has countless distractions vying for their attention and thus isn't in need of additional reasons to find something else to read. To be taken seriously, first use your words seriously.

Aquinas

To understand Aquinas's philosophy, such as his Five Ways, one must interpret Aquinas's arguments according to the Aristotelean metaphysics that underlies them. That's the main point of Feser's book Aquinas, and according to Feser, few modern philosophers interpret the arguments as such, instead interpreting them according to different metaphysics frameworks or even ignoring metaphysics altogether and taking a scientific, empirical view.

Feser devotes about ten dense pages to each Way, first describing the Way and then identifying various objections to the Way and how each objection fails according to an Aristotelean point of view. I gave an example of such an objection last Monday: To Aquinas, the common objection of the First Way, What moves God? makes no sense because God is unmoving.

And so it goes: many common objections to the Five Ways aren't objections but rather misconceptions. However, I won't describe the Ways here, nor will I enumerate the misconceptions; there are other things I find more interesting and I wish to move on. Suffice it to say if you're interested in sharpening your understanding of classical monotheism—and I think that's a worthwhile goal for nearly anyone—you can read Feser's book, settle for Feser's blog, or probably find other authors who have made similar points.

Instead, I'm going to jump straight to commentary.

After finishing the chapter on theology, I feel that Aquinas's Five Ways are solid arguments and atheists who argue against them are usually misguided. That differs from my opinion before starting Feser's book, back when I agreed with some of the common objections because I didn't interpret the Ways according to their Aristotelean premises. That said, Feser cemented my preexisting opinions that (1) Aristotelean metaphysics aren't compelling and (2) the God proved by classical monotheism has little to do with the God that monotheists actually worship.

Indeed, starting with the second point, I felt disappointed that the divine attributes turned out to be the well known infinite qualities such as immutability, eternalness, immaterialness, perfection, supreme simplicity, and so on. These attributes suggest God is another word for impersonal, unfeeling law or order, as in the kind of universal regularity that scientists try to discover through empirical investigation. Indeed, I find the Five Ways to be an interesting set of arguments for the claim that the universe is merely bound and that an absolutist view of things—rather than a relativistic view—makes the most sense ultimately. And here I use the word bound instead of finite because a thing may be infinite yet bound, such as how an endless string of 0's is infinite though possessing a fixed, limited quantity of information. Analogously, the Five Ways suggest the universe, irrespective whether it's finite or infinite, may be bound and thus ultimately subject to scientific law.

That brings me to my first point, which is that I don't find the Ways' underlying metaphysics to be compelling.

Pardon my metaphysics

At the heart of the problems I have with Aquinas's premises is his distinction between form and matter. To me, this distinction is dubious.

The key idea underlying form-matter dualism is that not everything can be material stuff alone—material stuff being matter and energy (and possibly spacetime itself?). Skipping past awkward, macroscopic examples of rubber balls highlighting the difference between rubber as matter and ball as form, there's the idea that concepts, like say, triangularity, necessitate the existence of something beyond mere material stuff. Such matterless things are forms. In the case of triangularity, a triangle is a conceptual thing independent of matter and thus exists as pure form.

Do forms exist as tangible things as though in another realm? Unlike Plato, Aquinas doesn't think so, and in any event we have no evidence for it. But maybe forms are merely mental—i.e., projections humans place onto the universe they observe. Not so, for even if all humans vanished triangles would still exist. For example, the angles of a triangle in Euclidean space add up to 180 degrees regardless whether there are any humans around to appreciate that fact.

So do triangles exist even if no material stuff exists anywhere in the universe? Aquinas thinks so, but this is an open question. Unlike the scenario whereby humans and only humans vanish, if all matter, energy and spacetime vanish then it's unclear what, if anything, remains. This leads to our most basic questions of what reality is all about.

For all I know, Aquinas answers the question correctly. But we can't be sure, and so (I think) it's better to build one's understanding of the universe around what one does know, even if that entails starting with the macroscopic stuff in the middle and using lenses to focus on bigger and smaller things over time. I just can't stop looking at things empirically.

Moving on

As Shelly Kagan jokes in the second lecture of his course on Death (which is open courseware, meaning you can freely read, listen to, or watch all the lectures—oh, how the Internet is a treasure!):

[You] will hear on several occasions over the course of the semester, I'm a philosopher. What that means is I don't really know a whole lot of facts.

Before starting Philosophy Monday on JEC, my intention was to read and blog about one book on polytheism (check!) and one book on monotheism (check!—though I'm ignoring the chapters on the soul and on ethics) and then move on to indulge myself in what really interests me: secularism. And in particular: secular ethics. My plan was to read and blog about Derek Parfit's quietly influential book, Reasons and Persons, which explores just how bizarre rational ethics is.

But those first two philosophy books have left me starved for facts, so I'm changing plans. Instead, I've started Sean Carroll's book, From Eternity to Here: The Quest for the Ultimate Theory of Time. It's a popular-level science book about cosmology and time. I'm unsure how inspiring it will be for Philosophy Monday material, but on the other hand I've got other things on my mind worth writing about.

The only real freedom

Two jobs ago I worked with a guy named Randy. Randy was a middle-aged developer who had a single-digit employee number and more years with the company than I had with life. He was an opinionated Republican and social conservative, a Vietnam Vet, and an enthusiast of a generally strange view of the world. So when I was assigned to help Randy port his disk storage software from Windows to Linux, we hit it off.

The two of us spent countless hours in his office, half working and half shooting the breeze. I figured that since the company paid me half what I was worth—as I figured it—and that since Randy came and went as he wished anyway, our arrangement with the company's time was fair.

Randy and I rarely agreed about anything philosophical, but one thing we did agree on was the inseparable link between money and freedom. As Randy put it many times: the only real freedom is financial freedom.

Now, civil rights are important freedoms. The right to free speech and the right to due process are important freedoms—critical freedoms. But no rights or freedoms granted to you by any parchment or legal act will keep you from becoming someone's tool, someone's serf. To be your own person, you must have your own wealth. Otherwise, someone will be there to tell you to show up to work on days you'd rather not show up, on days you're inspired to create something of your own, and thus you must drudge through the mediocrity of earning a living.

These last six months I've taken what many people would call a sabbatical. Six months ago I decided I was better off leaving my job, and so I left it. It was that simple. I left because I wanted to and I could. I took the time off to be myself, to set goals for myself. I learned two new programming languages. I made a bike rack and shoe rack. I read philosophy and then moseyed around the neighborhood to think about what I read. I nursed an Achilles' tendon injury. I bonded with Laura's cats.

Sadly, though I'm not fully shackled, neither am I fully free. And so I'm bringing my six months of self-direction to its end. Today I accepted a job offer and will be going back to work.

The new job has a few things going for it. For one, the company makes chargers for electric cars, which is cool even for a product, and making products beats making services. Also, the office is in downtown, and I love downtowns, even Phoenix's, what with their plazas and gigantic public art and their compactness that lets you walk to nearby shops and restaurants. Not that I spend money at shops or restaurants. But it's neat to be one of the shabbily dressed people who walks around, awkwardly staring people in the eye and muttering under his breath.

Proof from motion

Onward, out of the mire of metaphysics and on to firm ground!

The First Way—the proof from motion—is one of Thomas's five arguments for the existence of God. It goes something like as follows:

1. Motion—i.e., change—is caused by something that already exists.
2. Nothing can be both moved and mover at the same time.
3. There can be no infinite regression of movers.
4. Thus, for any given motion, there must exist a first mover—an unmoved mover—and that is taken to be God.

After describing the First Way, Feser raises the common objections and explains why the objections fail. For example:

Objection: The first mover could be anything; this proof doesn't say anything about God.
Answer: The First Way doesn't intend to prove the existence of God. Rather, it shows that if God exists then God should have, among other properties, the property of being a first mover. Other parts of the Summa Theologiae ascribe the divine attributes to the first mover.

Objection: But what moves God?
Answer: Irrelevant, the proof doesn't claim God moves. God is pure act and thus, possessing no potency, doesn't move.

Objection: Why can't a series of causes—i.e., motions—regress to infinity?
Answer: Because they can't.

OK, Feser answered the third objection a little more rigorously than my three-word summary, but I found his answer lacking nevertheless. As for the first two objections, these are the kinds of ideas that drew my to learning about Thomism in the first place—that many of the common criticisms against classical monotheism are based on misconceptions of the underlying philosophy.

An infinite series of movers

Though he didn't convince me that there can exist neither an infinite series of movers nor a circular series of movers, Feser did answer a few of my questions I posed last week: specifically, that causes really do happen simultaneously with their effects and that the distinction between essence and accident is well defined.

Indeed, the difference between accidental causes and essential causes is that a series of accidental causes occur non-simultaneously whereas a series of essential causes happens simultaneously. This definition of essential causes differs from a casual, man-in-the-street view of causes, where we perceive things in the past to cause effects in the present or more recent past and things in the present to cause effects in the future. Essential causes all happen now. For example, imagine a moving hand that moves a stick that moves a rock that moves a leaf. The motion of the hand is an essential cause for the motion of the stick, rock, and leaf, and all move together simultaneously.

Such a simultaneous series of causes can't regress to infinity. Why? I don't know, and this is one aspect of the explanation I found lacking. Another aspect I found lacking is whether any two causes in a series can ever happen simultaneously. Taking the view of modern physics' general relativity, where no information can travel faster than light, it seems safest to presume that there exists no series of essential causes greater than one. Just as we may define a three-sided polygon who angles sum to 270 degrees in Euclidean space, we're playing with a definition of a thing that doesn't exist. We know from experiment that the hand and the leaf really don't move simultaneously.

What the First Way doesn't say

The big idea I gleaned from Feser's explanation of the First Way is that the First Way isn't a proof for God's existence, though it's commonly marketed that way. Rather, the First Way is a conditional statement that goes something like as follows:

If motion is only caused by something that exists and if nothing can be both mover and moved at the same time and there can be no infinite regression of movers then motion is ultimately caused by something that itself doesn't move.

This seems valid to me. Interesting, though, what the First Way doesn't say. It doesn't say:

There can be only one first mover in the universe.

Nowhere do I see it argued or implied that all series of essential causes are themselves linked together to the same first mover. For example, two different hands and leaves moving about may have two distinct first movers. This is a point Greer made in his polytheism book: that with the exception of the Ontological Argument, all the arguments for the existence of one god work just as well as arguments for many gods. Thomas himself rejected the Ontological Argument, so I'm eager to see how he ascribes the divine attributes of a singular, infinite God to the being postulated by his Five Ways.

$4 lesson

Last week I took my touring bike to the shop after neglecting a repair job for a few months. The problem was that the left-hand brake lever component was loose and would slide up and down the handlebar when I put even a little force on it.

I do as much of my own bike maintenance as I can. Doing it myself serves two purposes: first, I learn skills and become less dependent upon specialized, paid-for help; and second, once I know what I'm doing, I do a better job than a paid-for mechanic does because I have more incentive not to be sloppy.

But I didn't know how to fix my brake-lever problem; I didn't know what needed to be tightened. I tried to figure it out by first peeling the rubber flap that covers the brake lever attachment to the handlebar, hoping that doing so would reveal the secret of what keeps the component in place, but that revealed nothing that could be adjusted. Next I peered into the component itself through the small space that opens behind the lever when the lever is squeezed. All I saw was a single tri-bit screw, and I figured that screw was loose and thus was my problem.

I had never before needed a tri-bit screwdriver when doing any bike maintenance, but I've long become accustomed to needing new, specialized bike tools. My latest tool acquisition was a cone wrench, which is an especially thin spanner wrench used for tightening the cones when replacing the bearings in older wheel axles, like those on my Benotto 10-speed.

So that's how I ended up at the bike shop with my touring bike, waiting to have the mechanic use a tri-bit screwdriver to tighten my brake lever. The mechanic took my bike into the back room. For the few minutes he worked on it I tried to watch what he was doing, but I couldn't see what he was doing without crossing into that strange, employees-only area, and I had to resort to asking him what he did when he was done.

Oh, I just used a —mm wrench, he said.

You mean a tri-bit screwdriver? I asked.

What? You don't need a screwdriver. He was now looking at me as though I'm a mechanics imbecile—which isn't far from the truth.

Yeah, I saw there's a tri-bit screw head in the component. Isn't that what you tightened?

What? No. There's a hex bolt right there that adjusts the tightness.

I then took another look inside the brake lever, which I should add is black and made darker from looking in through a small hole with poor lighting. But now knowing what I was looking for, I discerned the grays of a hex bolt easily accessible through the small hole. Now this repair job made sense: nearly everything that can possibly need tightening on a bike is tightened with a hex wrench, and the brake lever's attachment to the handlebar is no exception. That tri-bit screw is only an internal piece of the brake-lever component and never intended for adjustment.

I asked the mechanic what I owed him, and he said four dollars. I paid the four dollars and thanked him for making me feel stupid—but also smarter.

Thomism C.A.Q.

I now doubt I chose a good book for learning about Thomism. It's not that Edward Feser's book isn't good—it may very well be. Rather, when reading Feser's commentary, I feel like I've imposed upon a heated exchange between a Red Sox fan and a Yankees fan: an argument that's been going on a lot longer than I've been alive and is about something I don't care much about. In this case, the argument is between philosophers and is about things philosophers care about—non-falsifiable claims science expelled as irrelevant a long time ago. But I've imposed upon the exchange between the two fans, and now one of them is telling me I'm mistaken for not caring about the Red Sox and Yankees and I ought to take a side.

Thomists and Catholics, like most people in the world, wish more people listened to them and took them seriously. But to be taken seriously you must first take other viewpoints seriously, if only to understand how to phrase your explanations to people who see things differently. I want a book about Thomism that takes my viewpoint seriously and then explains Thomism's relevance.

The book about Thomism I'd like to read would be written for people who aren't impressed with metaphysical systems just because they possess internal logical consistency—i.e., claims ultimately backed with you can't prove me wrong. The book would start with the assumption that the reader takes a skeptical view towards uses of the word natural and would start with Gödel and Chaitin and logical incompleteness, and go from there to show Thomism still matters even after knowing these things. Does such a book, however unmarketable, exist?

I doubt it, and I won't be the one to write it because I don't understand Thomism. Instead, today I'm posting my ignorance in the form of a CAQ—Craig-Asked Questions—questions I derived from the notes I jotted in the margins besides my main notes from Feser's book. These notes pertain only to the chapter on metaphysics.

---

Note: Unlike FAQs, CAQs don't have answers, just more befuddlement.

How does one know which potentialities of an object are natural and which are unnatural?

Using Feser's example, rubber balls don't bounce from here to the moon, nor do they move by themselves and follow people menacingly, because they lack the potential to do so—i.e., such potentialities are unnatural. What then is the definition of natural?

Forms are abstractions, but is matter not an abstraction, too? If it's not an abstraction, what then is matter made of?

This reminds me of my philosophical position on atoms: atoms don't actually exist, but they're useful constructs to keep in mind when reading a chemistry textbook. Ditto for circles with respect to math textbooks.

Are substantial and accidental forms relative?

Using Feser's example, painting a ball a different color causes the ball to lose one accidental form (i.e., non-essential form) and take on another accidental form, but the ball's substantial form of being a ball remains. But perhaps instead of saying we started with a ball that happened to be, say, red, we said we started with a red thing that happened to be in the shape of a ball. In such a case, the accidental and substantial forms would be flipped. Is this a valid way to think about the metaphysical truth of the universe? If so, are there limits to how relativistic accidental and substantial forms are? Without limits, there exists an infinite combination of accidental and substantial forms that may be applied to any one thing.

If substantial and accidental forms aren't relative or are limited relativistically, then what criteria ought we use for determining them?

And how do we justify the criteria themselves? And how do we justify the justification of the criteria? And so on.

What are the final causes of stochastic radiation?

Is chance event a valid final cause? If so, how do we know when chance event isn't the final cause of something?

If causes happen simultaneously to their effects then how does motion occur at all?

I suspect I missed something here. According to Feser's example of a brick smashing through a window, the brick pushing into the glass and the glass giving way are simultaneous events—indeed, actually the same event considered under different descriptions. But cause-and-effect are used to explain change, and saying that a cause and its effect are simultaneous implies a sort of Zeno's paradox whereby change cannot occur. What did I miss?

Are final causes and privations relative?

This deserves a story. I once remarked to my former coworker Shafik how it bugged me that electrons in electrical circuits flow from negative to positive, all due to Benjamin Franklin's arbitrary 18th century terminology. Because of Franklin, a positive potential signifies a negative concept: a lack of electrons.

Shafik put me to ease with an idea so simple it frustrates me I didn't think of it myself: Craig, if the terminology bugs you, then think of a positive potential not as a lack of electrons but rather as a positive desire to obtain electrons. Only because of mental feebleness does this cause electrical flow to make more sense to me.¹

Shafik's advice follows from a relativism heuristic that aids in understanding a lot of math and science: use whichever terminology makes the most sense of what you see. How does this heuristic apply to final causes and privations? For example, maybe the final cause of an eye is to see and cataracts are the result of a privation that hinders the final cause of sight. But maybe instead the final cause of an eye is the development of cataracts and all our early decades of clear sight are a privation of cataracts? Is any one system of terminology more valid than another? If so, what are the criteria for judging the validity of one final cause theory over another?

Why are final causes not tautologies?

(obligatory xkcd reference here)

Feser explicitly claims the notion of final causes is non-tautological, but he doesn't explain why. To Feser, the two statements:

Opium causes sleep because it causes sleep.

and

Opium causes sleep because it has the power to cause sleep.

are inequivalent. Why are they inequivalent? From the book:

[The second statement says] that opium has a power to cause sleep; that is to say, it tells us that the fact that sleep tends to follow the taking of opium is not an accidental feature of this or that sample of opium, but belongs to the nature of opium as such.

That leads us back to the question of the relativism of accidental and substantial forms and how we judge one accidental-substantial pair as more valid than another. It seems Thomism hinges on a preformed notion of natural.

What's insufficient about the distinction between context-free and context-specific that makes final causes necessary for understanding the significance of a given causal chain?

Feser gives the example of how bear DNA causes bears to be big and furry but bear DNA doesn't cause bears to be good mascots for football teams. Feser's point is this implies there's a final cause at work with DNA, and the final cause includes size and furriness but not mascot-worthiness.

But bear DNA does cause bears to be good mascots, just not directly. The issue here is the distinction between context-free and context-specific causalities, not end causes. Bear DNA causes bears to be big and furry regardless whether humans exist, but whether bear DNA causes them to be good mascots also depends upon (1) humans existing; (2) humans playing football; and (3) humans choosing mascots that are big, furry animals. Biologists don't study mascot-worthiness genes in DNA because such genes require context that transcends the scope of biology—but the genes exist nevertheless.

What's the final cause of a final cause?

And what's the final cause of a final cause's final cause?, and so on. How do final causes work at all without leading to an infinite regression?—or are we allowing for infinite regressions?

By the way—and this isn't a question—a decrease in entropic order is an increase in information.

From the book:

…would contradict the second law of thermodynamics, which tells us that order (and thus information content) tends invariably to decrease, not increase, within a closed system.

Not to pick on Feser here because this is a common misconception: order is a lack of information, and the amount of information in a closed system increases with time as order decreases. As with electrons and the flow of electrical current, many people see this as a backwards way of looking at things. If you're such a person, try thinking of order as a reduction in complexity or a kind of data compression.² For example, if you sort your books according to the Dewey Decimal System then you need only a simple, concise card catalog to describe where any book is; without sorting your books to some such system, you need more information to describe where any book is.

^[1] The backwards terms for electrical charges are useful for pointing out that electrical current is arbitrary. In batteries what flows are protons, not electrons, and the protons do flow from positive to negative.

^[2] But don't think of order as lossless data compression if you want to be exact about it because lossless data compression doesn't eliminate information; instead, it squeezed a fixed amount of information into a smaller space.