William M. Briggs

Statistician to the Stars!

Page 2 of 414

Summary Against Modern Thought: God Is Not Made Of Matter

This may be proved in three ways. The first...

This may be proved in three ways. The first…

See the first post in this series for an explanation and guide of our tour of Summa Contra Gentiles. All posts are under the category SAMT.

Previous post.

A relatively simple argument today. God is not made of stuff. Who would disagree? Pagans, perhaps. For example, the god of the atheists is a demiurge, a sort of superior created or “evolved” being, and therefore made of matter. But not God. What’s nifty about today’s discussion is the role of “chance”. For that, we turn back (again) to Aristotle.

Chapter 17: That in God there is no matter

1 FROM this it follows that God is not matter.i

2 For matter, such as it is, is in potentiality.ii

3 Again. Matter is not a principle of activity: wherefore, as the Philosopher puts it,[1] efficient and material causes do not coincide. Now, as stated above,[2] it belongs to God to be the first efficient cause of things. Therefore He is not matter.iii

4 Moreover. For those who referred all things to matter as their first cause, it followed that natural things exist by chance: and against these it is argued in 2 Phys.[3] Therefore if God, Who is the first cause, is the material cause of things, it follows that all things exist by chance.iv

5 Further. Matter does not become the cause of an actual thing, except by being altered and changed. Therefore if God is immovable, as proved above,[4] He can nowise be a cause of things as their matter.v

6 The Catholic faith professes this truth, asserting that God created all things not out of His substance, but out of nothing.vi

7 The ravings of David of Dinant are hereby confounded,vii who dared to assert that God is the same as primary matter, because if they were not the same, they would needs differ by certain differences, and thus they would not be simple: since in that which differs from another thing by a difference, the very difference argues composition.

Now this proceeded from his ignorance of the distinction between difference and diversity. For as laid down in 10 Metaph.[5] a thing is said to be different in relation to something, because whatever is different, differs by something, whereas things are said to be diverse absolutely from the fact that they are not the same thing.[6]

Accordingly we must seek for a difference in things which have something in common, for we have to point to something in them whereby they differ: thus two species have a common genus, wherefore they must needs be distinguished by differences. But in those things which have nothing in common, we have not to seek in what they differ, for they are diverse by themselves. For thus are opposite differences distinguished from one another, because they do not participate in a genus as a part of their essence: and consequently we must not ask in what they differ, for they are diversified by their very selves. Thus too, God and primary matter are distinguished, since, the one being pure act and the other pure potentiality, they have nothing in common.

—————————————————————-

iFrom last time, of course.

iiMatter can change, thus it is in potentiality, and we have seen from last time that God is not in potentiality.

iiiThis doesn’t appear controversial, but we have scarcely outlined the nature of cause. There are four kinds of cause: the formal (the form of the thing), material (what the thing is made of), efficient (what brings about the change), and final (the end or direction of the change). The material of the statue, say, is not its efficient cause. Much more on this later.

ivWe are now at Yours Truly’s favorite material. Aristotle (from 2 Phys iv):

Some people even question whether [chance and spontaneity] are real or not. They say that nothing happens by chance, but that everything which we ascribe to chance or spontaneity has some definite cause, e.g. coming ‘by chance’ into the market and finding there a man whom one wanted but did not expect to meet is due to one’s wish to go and buy in the market.

Similarly in other cases of chance it is always possible, they maintain, to find something which is the cause; but not chance, for if chance were real, it would seem strange indeed, and the question might be raised, why on earth none of the wise men of old in speaking of the causes of generation and decay took account of chance; whence it would seem that they too did not believe that anything is by chance…

There are some too who ascribe this heavenly sphere and all the worlds to spontaneity. They say that the vortex arose spontaneously, i.e. the motion that separated and arranged in its present order all that exists. This statement might well cause surprise.

For they are asserting that chance is not responsible for the existence or generation of animals and plants, nature or mind or something of the kind being the cause of them (for it is not any chance thing that comes from a given seed but an olive from one kind and a man from another); and yet at the same time they assert that the heavenly sphere and the divinest of visible things arose spontaneously, having no such cause as is assigned to animals and plants.

Yet if this is so, it is a fact which deserves to be dwelt upon, and something might well have been said about it. For besides the other absurdities of the statement, it is the more absurd that people should make it when they see nothing coming to be spontaneously in the heavens, but much happening by chance among the things which as they say are not due to chance; whereas we should have expected exactly the opposite.

Others there are who, indeed, believe that chance is a cause, but that it is inscrutable to human intelligence, as being a divine thing and full of mystery.

Aristotle says things which are for the sake of something can be caused by chance, and he gives this example (2 Phys v):

A man is engaged in collecting subscriptions for a feast. He would have gone to such and such a place for the purpose of getting the money, if he had known. [But he] actually went there for another purpose and it was only incidentally that he got his money by going there; and this was not due to the fact that he went there as a rule or necessarily, nor is the end effected (getting the money) a cause present in himself — it belongs to the class of things that are intentional and the result of intelligent deliberation. It is when these conditions are satisfied that the man is said to have gone ‘by chance’. If he had gone of deliberate purpose and for the sake of this — if he always or normally went there when he was collecting payments — he would not be said to have gone ‘by chance’.

Notice that chance here is not an ontological (material) thing or force, but a description or a statement of our understanding (of a cause). Aristotle concludes, “It is clear then that chance is an incidental cause in the sphere of those actions for the sake of something which involve purpose. Intelligent reflection, then, and chance are in the same sphere, for purpose implies intelligent reflection.”

And “Things do, in a way, occur by chance, for they occur incidentally and chance is an incidental cause. But strictly it is not the cause — without qualification — of anything; for instance, a housebuilder is the cause of a house; incidentally, a fluteplayer may be so.”

Chance used this way is like the way we use coincidence. But there is also spontaneity, which is similar: “The stone that struck the man did not fall for the purpose of striking him; therefore it fell spontaneously, because it might have fallen by the action of an agent and for the purpose of striking.”

Lastly, “Now since nothing which is incidental is prior to what is per se, it is clear that no incidental cause can be prior to a cause per se. Spontaneity and chance, therefore, are posterior to intelligence and nature. Hence, however true it may be that the heavens are due to spontaneity, it will still be true that intelligence and nature will be prior causes of this All and of many things in it besides.”

vIn short, since God is not movable, he can’t be made of matter, which is always movable.

viSuch a misunderstood word, nothing! It means just what it says. No thing. No fields, no forces, no fields, no equations, no quantum thises or thats, the absence of all entities. Now just you imagine what kind of Being could create something about of this real nothing. Only one: Being itself, I Am That I Am; which is to say, God.

viiZing! More proof that even saints can be contemptuous when the need arises. Notice very carefully that St Thomas does not ask for dialogue with David of Dinant, but is satisfied to destroy his argument.

[1] 2 Phys. vii. 3.
[2] Ch. xiii.
[3] Chs. viii., ix.
[4] Ch. xiii.
[5] D. 9, iii. 6.
[6] Sum. Th. P. I., Q. iii., A. 8, ad 3.

Ask A Scientific Ethicist: Baby Making, Auto Mishap, ISIS Attacks

The Scientific Ethicist, PhD

The Scientific Ethicist, PhD

This was supposed to run this morning. No idea why it didn’t.

This week, three letters from concerned readers.

Too many babies

Dear Scientific Ethicist,

Hopefully this subject matter isn’t too technical for your audience.

In a recent discussion with my boss, I claimed that it was impossible for nine women to make a baby in one month. My boss claimed that with proper planning, nine women could indeed have a baby a month for nine months.

Which one of us is correct? No pressure intended, but I think my job might be dependent on your answer.

Thanks,

Milton

Dear Milton,

Your boss is right. Nine (biological) women could, with appropriate planning, have one baby each, one per month spaced equally over nine months.

And you’re wrong. Nine women could indeed make one baby in one month. As long as they had access to an egg from any one of them, certain male genetic material, which Science shows can be had any old place, and some rather sophisticated medical equipment (made by Science!). The baby could be made—and in well under one month, at that—and implanted in any of the women. This isn’t the best, safest, surest, or recommended method—it’s too easy to kill the baby because creation and implantation—but the thing can be done.

Of course, Science tells us that baby would take approximately nine months to emerge from its mother. But that’s birth, and not the making of it.

Unfortunately, Science disagrees with you. But if it’s any consolation, Science disagrees with a lot of people!

The Scientific Ethicist

Automotive mishap

Dear Scientific Ethicist,

I was driving down the road and saw a car crash into a parked car, then drive away without leaving a note. There was just a little damage on the parked car. I took down the the licence plate number of the car that drove off, but it was being driven by a young ethnic woman, and I don’t want to be a racist. What should I do in this situation?

[Name Withheld], Atlanta, GA

Dear [Name Withheld],

The force between an average car going at typical speeds (in the neighborhood of 30 MPH) hitting a stationary average car is easily calculated. We call this momentum, the mass of the car multiplied by its velocity. In many cases, we can speak of the momentum as a single variable instead of trying to keep track of multiple measures.

If both cars were moving, then depending on the directions both cars were traveling, there could have been at the time of contact anything from very little momentum, to something quite high. But since one car was not moving, the momentum probably wasn’t large.

Low momentum impacts produce notably less damage than high momentum impacts. That you say “just a little damage” indicates that this was probably a low momentum impact.

Once again, Science gives the answer!

The Scientific Ethicist

Take that man

Dear Scientific Ethicist,

I live in Al Bukamal, Syria. The Islamic State is practically out the back door. They’re beheading non-Muslims, burying children alive for not being Muslims, and many other terrible things. And they’re boasting of it! Oosting pictures of it on the web. The terror endless. I’m starting to panic. What should I do to stay calm?

Billy, San Francisco

Dear Billy,

Only the consolations of Science can have any effect. I usually recommend reading Introduction to Topology by Bert Mendelson, or Inorganic Chemistry by Gary Wulfsberg. Though in your case, nothing is better suited than Brian Greene’s The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos.

In that book, Greene highlights the Science of the multiverse. The gist is that there are an infinite number of other universes where you also exist and where the Islamic State is benign. Why, there’s even a universe in which each member of ISIS is a Good Humor man handing out free ice cream to children over-heated by the desert! In none of these other happy universes would you feel terror.

Science can calm the most troubled soul!

The Scientific Ethicist

Send in your questions to the Scientific Ethicist today! Or read his previous columns.

It Makes No Sense To Say You’re More Likely To Die Of Bee Sting Than Shark Bite

"Tell the world. Tell this to everybody, wherever they are. Watch the skies everywhere. Keep looking. Keep watching the skies."

“Tell the world. Tell this to everybody, wherever they are. Watch the skies everywhere. Keep looking. Keep watching the skies.”

The National Journal says: “The odds of being killed by a shark are about 1 in 3.7 million. The odds of being killed by a sting from a bee, wasp, or hornet are 1 in 79,842, according to the National Center for Health Statistics, a part of the Centers for Disease Control and Prevention.”

Now you see these kinds of stories all the time, all of which have conclusions like You have a better chance of dying in a lightning strike than in winning the lottery, etc., etc.

These stories are all wet. Nobody has a chance of dying in a lightning strike, just as nobody has a chance of winning the lottery or being killed by stinging sharks or biting wasps. By which I mean, everybody has a chance of winning the lottery or being stung by lightning or whatever.

Double talk? The problem is chance, a nebulous word, apt to change shape mid-sentence so that you don’t always end up where you were aiming.

In one version, chance means logical possibility. Everybody has the logical possibility of dying by shark, bee, or lightning. But chance also connotes probability. And there just is no unconditional probability of dying by anything.

Logical possibility is a weak criterion. Anything that isn’t logically impossible, such as square circles, is logically possible. You might be a native Antarctican, solid ice your bed and fluffy snow your pillow since birth. But, one day, an evil Polar Vortex might surreptitiously search the seas for your doom, and fling a hammerhead shark from the tropics to the very spot on which you take your morning ice floe stroll, as was illustrated in the documentary Sharknado.

Hey, it could happen. It’s logically possible. And in that sense you have a chance of dying by shark bite.

But you don’t have an unconditional probability of dying by one. What can we say? If the probability of you being eaten by a shark were 0, then it would be impossible, logically impossible, that you could be eaten by a shark. But we’ve already agreed that it is logically possible. And if your probability is 1, then that means the universe guarantees, no matter what, you will have your head bit off. Ouch.

This means the probability of you dying by shark bite, without knowing anything else about you (and I mean this clause just as it’s written), is no number at all, but all numbers between 0 and 1. Which is fairly useless, as far as information goes, But not entirely unless since non-extreme probability tells us a event is contingent, i.e. logically possible.

We can now see that it makes no sense to say the unconditional probability of dying by a bee sting is “larger” than of suffering the consequences of a sharknado. These probabilities, in the absence of any other information, are equal.

What “other information”? Example: your aunt Narantsetseg lives in central Mongolia, far from the sea and inland aquariums, whilst you live in Key Largo in a beach shack. Given only this information, which includes common knowledge about these locations and their nearness to sharks, it’s natural to say you have a larger probability of dying of shark bite than your aunt.

How much larger? We don’t know. There’s still not enough information to quantify the difference. Why? All probability is conditional on the information supplied. If that information is vague, as it is in the maximal sense when we know noting other than the event in logically possible, no quantification is possible. To get numbers, we need specific information.

Enter the the Frequentist Fallacy. Happens like this. American citizens killed by shark bites are divided by the population, and this number is substituted for the probability of you yourself dying from shark bite. This “probability” is assigned to beach dwellers and Norther Michiganders alike. Which is silly, because, obviously, the information for these folks is radically different, and thus so are their (conditional) probabilities.

So is dying of a bee or wasp sting more probable than by shark bite? We now see that it makes no sense to ask this. If you can’t swim and are allergic to bee stings and live next to an apiary, then it’s more likely you’ll die from a sting than a shark bite. But if you live in Key West and go snorkeling daily and aren’t allergic to bees, it’s more likely you’ll die inside the innards of a shark.

How much more likely (in either case) we can’t say.

———————————————————————

Thanks to Brad Tittle for suggesting this topic.

Decline Of Participation In Religious Rituals With Improved Sanitation

All the world's religions, in bacterial form.

All the world’s religions, in bacterial form.

Answer me this. Earl at the end of the bar, on his sixth or seventh, tells listeners just what’s wrong with America’s science policy. His words receive knowing nods from all. Does this action constitute peer review?

Whatever it is, it can’t be any worse than the peer review which loosed “Midichlorians—the biomeme hypothesis: is there a microbial component to religious rituals?” on the world. An official paper from Alexander Panchin and two others in Biology Direct, which I suppose is a sort of bargain basement outlet for academics to publish.

The headline above is a prediction directly from that paper, a paper so preposterous that it’s difficult to pin down just what went wrong and when. I don’t mean that it is hard to see the mistakes in the paper itself, which are glaring enough, for all love. No: the important question is how this paper, how even this journal and the folks who contribute to it, can exist and find an audience.

Perhaps it can be put down to the now critical levels of the politicization of science combined with the expansion team syndrome. More on that in a moment. First the paper.

It’s Panchin’s idea that certain bugs which we have in our guts make us crazy enough to be religious, and that only if there were a little more Lysol in the world there would be fewer or no believers.

Panchin uses the standard academic trick of citing bunches of semi-related papers, which give the appearance that his argument has both heft and merit. He tosses in a few television mystery-show clues, like “‘Holy springs’ and ‘holy water’ have been found to contain numerous microorganisms, including strains that are pathogenic to humans”. Then this:

We hypothesize that certain aspects of religious behavior observed in human society could be influenced by microbial host control and that the transmission of some religious rituals could be regarded as a simultaneous transmission of both ideas (memes) and organisms. We call this a “biomeme” hypothesis.

Now “memes” are one of the dumbest ideas to emerge from twentieth-century academia. So part of the current problem is that dumb ideas aren’t dying. Capital-S science is supposed to be “self correcting”, but you’d never guess it from the number of undead theories walking about.

Anyway, our intrepid authors say some mind-altering, religion-inducing microbes make their hosts (us) go to mass, or others to temple, and still more to take up posts as Chief Diversity Officers at universities just so that the hosts will be able pass on the bugs to other folks. Very clever of the microbes, no? But that’s evolution for you. You never know what it’ll do next.

Okay, so it’s far fetched. But so’s relativity—and don’t even get started on quantum mechanics. Screwiness therefore isn’t necessarily a theory killer. But lack of consonance with the real world is. So what evidence have the authors? What actual observations have they to lend even a scintilla of credence to their theory?

None.

Not one drop. The paper is pure speculation from start to finish, and in the mode of bad Star Trek fan fiction at that.

So how did this curiosity (and others like it) become part of Science? That universities are now at least as devoted to politics as they are to scholarly pursuits is so well known it needs no further comment here. But the politics of describing religion as some sort of disease or deficiency is juicy and hot, so works like this are increasingly prevalent. Call them Moonacies, a cross between lunacies and Chris Mooney, a writer who makes a living selling books to progressives who want to believe their superiority is genetic.

Factor number two, which is not independent of number one, is expansion team syndrome. The number of universities and other organizations which feed and house “researchers” continue to grow, because why? Because Science! We’re repeatedly told, and everybody believes, that if only we all knew more Science, then the ideal society will finally have been created. Funding for personnel grows. Problem is, the talent pool of the able remains fixed, so the available slots are filled with the not-as-brilliant. Besides, we’re all scientists now!

New journals are continuously created for the overflow, and they’re quickly filled with articles like this one giving the impression things of importance are happening. Not un-coincidentally, these outlets contain greater proportions of papers which excite the press (no hard burden). And so here we are.

Comments On Dawid’s Prequential Probability

Murray takes the role of a prequential Nature.

Murray takes the role of a prequential Nature.

Phil Dawid is a brilliant mathematical statistician who introduced (in 1984) the theory of prequential probability1 to describe a new-ish way of doing statistics. We ought to understand this theory. I’ll give the philosophy and leave out most of the mathematics, which are not crucial.

We have a series of past data, x = (x1, x2, …, xn) for some observable of interest. This x can be quite a general proposition, but for our purposes suppose its numerical representation can only take the values 0 or 1. Maybe xi = “The maximum temperature on day i exceeds Wo C”, etc. The x can also have “helper” propositions, such as yi = “The amount of cloud cover on day i is Z%”, but we can ignore all these.

Dawid says, “One of the main purposes of statistical analysis is to make forecasts for the future” (emphasis original) using probability. (It’s only other, incidentally, is explanation: see this for the difference.)

The x come at us sequentially, and the probability forecast for time n+1 Dawid writes as Pr(xn+1 | xn). “Prequential” comes from “probability forecasting with sequential prediction.” He cites meteorological forecasts as a typical example.

This notation suffers a small flaw: it doesn’t show the model, i.e. the list of probative premises of x which must be assumed or deduced in order to make a probability forecast. So write pn+1 = Pr(xn+1 | xn, M) instead, where M are these premises. The notation shows that each new piece of data is used to inform future forecasts.

How good is M at predicting x? The “weak prequential principle” is that M should be judged only on the pi and xi, i.e. only how on good the forecasts are. This is not the least controversial. What is “good” sometimes is. There has to be some measure of closeness between the predictions and outcomes. People have invented all manner of scores, but (it can be shown) the only ones that should be used are so-called “proper scores”. These are scores which require pn+1 to be given conditional on just the M and old data and nothing else. This isn’t especially onerous, but it does leave out measures like R^2 and many others.

Part of understanding scoring is calibration. Calibration has more than one dimension, but since we have picked a simple problem, consider only two. Mean calibration is when the average of the pi equaled (past tense) the average of the xi. Frequency calibration is when whenever pi = q, q*100% of the time x = q. Now since x can only equal 0 or 1, frequency calibration is impossible for any M which does produce non-extreme probabilities. That is, the first pi that does not equal 0 or 1 dooms the frequency calibration of M.

Ceteris paribus, fully calibrated models are better than non-calibrated ones (this can be proven; they’ll have better proper scores; see Schervish). Dawid (1984) only considers mean calibration, and in a limiting way; I mean mathematical limits, as the number of forecasts and data head out to infinity. This is where things get sketchy. For our simple problem, calibration is possible finitely. But since the x are given by “Nature” (as Dawid labels the causal force creating the x), we’ll never get to infinity. So it doesn’t help to talk of forecasts that have not yet been made.

And then Dawid appears to believe that, out an infinity, competing mean-calibrated models (he calls them probability forecasting systems) are indistinguishable. “[I]n just those cases where we cannot choose empirically between several forecasting systems, it turns out we have no need to do so!” This isn’t so, finitely or infinitely, because two different models which have the same degree of mean calibration can have different levels of frequency calibration. So there is still room to choose.

Dawid also complicates his analysis by speaking as if Nature is “generating” the x from some probability distribution, and that a good model is one which discovers this Nature’s “true” distribution. (Or, inversely, he says Nature “colludes” in the distribution picked by the forecaster.) This is the “strong prequential principle”, which I believe does not hold. Nature doesn’t “generate” anything. Something causes each xi. And that is true even in the one situation where our best knowledge is only probabilistic, i.e. the very small. In that case, we can actually deduce the probability distributions of quantum x in accord with all our evidence. But, still, Nature is not “generating” x willy nilly by “drawing” values from these distributions. Something we-know-not-what is causing the x. It is our knowledge of the causes that is necessarily incomplete.

For the forecaster, that means, in every instance and for any x, the true “probability distribution” is the one that takes only extreme probabilities, i.e. the best model is one which predicts without error (each pi would be 0 or 1 and the model would automatically be frequency and mean calibrated). In other words, the best model is to discover the cause of each xi.

Dawid also has a technical definition of the “prequential probability” of an “event”, which is a game-theoretic like construction that need not detain us because of our recognition that the true probability of any event is 0 or 1.

Overall

That models should be judged ultimately by the predictions they make, and not exterior criteria (which unfortunately includes political considerations, and even p-values), is surely desirable but rarely implemented (how many sociological models are used to make predictions in the sense above?). But which proper score does one use? Well, that depends on exterior information; or, rather, on evidence which is related to the model and to its use. Calibration, in all its dimensions, is scandalously underused.

Notice that in Pr(xn+1 | xn, M) the model remains fixed and only our knowledge of more data increases. In real modeling, models are tweaked, adjusted, improved, or abandoned and replaced wholesale, meaning the premises (and deductions from the same) which comprise M change in time. So this notation is inadequate. Every time M changes, M is different, a banality which is not always remembered. It means model goodness judgments must begin anew for every change.

A true model is the one that generates extreme probabilities (0 or 1), i.e. the identifies the causes, or the “tightest” probabilities deduced from the given (restricted by nature) premises, as in quantum mechanics. Thus the ultimate comparison is always against perfect (possible) knowledge. Since we are humble, we know perfection is mostly unattainable, thus we reach for simpler comparisons, and gauge model success by it success over simple guesses. This is the idea of skill (see this).

Reminder: probability is a measure of information, an epistemology. It is not the language of causality, or ontology.

—————————————————————————–

Thanks to Stephen Senn for asking me to comment on this.

1The two papers to read are, Dawid, 1984. Present position and potential developments: some personal views: statistical theory: the prequential approach. JRSS A, 147, part 2, 278–292. And Dawid and Vovk, 1999. Prequential probability: principles and properties. Bernoulli, 5(1), 125–162.

« Older posts Newer posts »

© 2014 William M. Briggs

Theme by Anders NorenUp ↑