Thursday, December 31, 2015

Bourgeois Society

"To say that the market economy belongs to a basically bourgeois total order implies that it presupposes a society which is the opposite of proletarianized society, in the wide and pregnant sense which it is my continual endeavor to explain, and also the opposite of mass society as discussed in the preceding chapter. Independence, ownership, individual reserves, saving, the sense of responsibility, rational planning of one's own life -- all that is alien, if not repulsive, to proletarianized mass society." -- Wilhelm Röpke, A Humane Economy, p. 99

Monday, December 28, 2015

Why Trump Is Popular

A very good analysis from David Frum, here.

I'd add that it's not so much his particular policies, as the fact he ticks off the "right" people.

Sunday, December 27, 2015

Linear Programming Bleg

I am working on learning how to do linear programming in Excel; I would like to do this for my production possibility frontier model. Is there anyone out there who wouldn't mind mentoring me a little on this?

Some Macro Models

In Excel, posted to GitHub. Right now I have:
  • A real growth vs. nominal growth vs. inflation spreadsheet
  • A Keynesian Cross spreadsheet; and
  • A Production Possibility Frontier spreadsheet.
All of them are built on a minimal data entry paradigm; for instance, for the Keynesian Cross, you only need enter autonomous consumption, marginal propensity to consume, and intended investment, and the whole kit and caboodle recalculates from there. For the PPF, you just enter a maximum number of units, and everything recalculates: great for showing a collapsing or expanding PPF.

Models are not about "essentials"...

They are abstractions that highlight an aspect of the thing being modeled.

That is why I deny that, by making a model of a recession in which "recessions are not about output and employment and saving and investment and borrowing and lending and interest rates and time and uncertainty... the only essential things are a decline in monetary exchange caused by an excess demand for the medium of exchange," Nick Rowe has shown that in real recessions, those are the only essential things.

For instance, what about the proposition that "The Ptolemaic model of the solar system proves that it is not about rock-and-ice-and-gas planets orbiting a giant plasma orb: The only essential thing is pure circular movement"?

But perhaps the problem there is that that is not a good model. So let's say we get a better one: Newton's. Now we have a planet as a point mass, orbiting the Sun, another point mass. Is this the "essence" of the solar system? That doesn't seem right at all: these point masses aren't the essence of planets and the Sun. They are just an abstraction of one aspect of these bodies, among countless others they possess. And for different problems, a model based on the idea of point masses would be disastrously misleading: You don't want to try to land your spacecraft on Mars based on modeling it as a point mass, nor would humans survive long if the Earth were one!

In particular, one may question whether, in Rowe's model which purports to show that recessions are all about "an excess demand for the medium of exchange," there is really a medium of exchange at all. Consider this quote from Mises:

"Thus the 'money' of this system is not a medium of exchange; it is not money at all; it is merely a numéraie, an ethereal and undetermined unit of accounting of that vague and indefinable character which the fancy of some economists and the errors of many laymen mistakenly have attributcd to money. The interposition of these numerical expressions between seller and buyer does not affect the essence of the sales..." -- Human Action

Let us look at what role "mangoes" play in the model economy Rowe has created. In his barter economy, he makes mangoes the "numéraie," and shows how the "price" of apples and bananas in terms of mangoes makes no difference to what trades take place at all. But in what sense, then, are these "prices" at all? What possible actors would choose to evaluate their trades in terms of a "price" that made no difference to what they traded? If we want to look at "essences," I would suggest that the "essential" feature of any price is that it enables us to evaluate whether or not some exchange is worthwhile.

Rowe then proceeds to a model where apples are not traded directly for bananas, but each are traded for mangoes. Why don't actors simply trade apples directly for bananas in this economy? He says:

"This means there is a market in which mangoes are traded for apples (the 'apple market'), and a market in which mangoes are traded for bananas (the 'banana market'), but no market in which apples are traded for bananas directly. The reason is that mangoes are portable, but apples and bananas must be eaten directly off the tree, or they taste bad, and agents are anonymous so can't swap IOUs for apples or bananas. So the only way agents can trade apples and bananas is by using mangoes as the medium of exchange."

Rowe recognizes that, even in the case where apples and bananas can only be eaten directly from their trees, IOUs could suffice to permit exchange: each actor could signal, through whatever IOU mechanism they employ, "You can go eat 100 of my apples, if I can go eat 100 of your bananas." And he tries to foreclose this possibility by positing that "agents are anonymous." But what in the world can that mean? I just go and dump 10 mangoes out on the beach, and trust that somehow ten bananas will appear in exchange? No, if transacting agents are anonymous to each other, then they must have some exchange through which they are transacting, and that exchange must know the identity of each transacting agent. If I offer ten mangoes for ten bananas, then for me to have any faith that I simply haven't lost my mangoes, someone or something (e.g., a computer) must know exactly who has accepted my offer, and have some way to ensure that non-anonymous agent actually delivers. In which case, we could simply transact through IOUs, and skip the mangoes.

Finally, let us assume that, for some unknown reason, mangoes would actually serve as the medium of exchange in Rowe's model. A recession sets in when people suddenly desire to hold more mangoes than they previously had held, raising P above 1. But what could possibly cause such a price change except increased uncertainty about the future? Indeed, what could ever create the need for a medium of exchange at all, except uncertainty about the future?

Rowe's model is interesting, and I am glad he has forwarded it. But it does not prove what he thinks it proves.

Friday, December 25, 2015

Rational eating

I encountered an article recently -- I am not going to bother even looking it up and linking to it, because similar sentiments are a dime a dozen -- arguing that the American way of using a fork while eating is "inefficient," and thus should be replaced by a more European style.

But... what does "efficiency" have to do with table manners? If our goal, when sitting down at the table, was to simply get food as "efficiently" as possible into our mouths, we would just plunge our face down into our dish, the same way our dogs eat.

Civilized eating is precisely about checking our tendency to eat like an animal, and constraining our appetite according to cultural rules as to how we may eat. To evaluate our table manners based on whether the American way of eating with a fork is more or less "efficient" than eating with chopsticks, or one's fingers, is to completely misconstrue what table manners are about: they exist to reduce our "efficiency" in gobbling down our food, to turn our eating experience from that of a hungry animal gulping down whatever it can as fast as it can, to that of a civilized being constraining its eating according to social rules.

"You're so behind the times!"

Intellectually, the above is the equivalent of "You think differently than we do in my province!"

"The times" is just the province of the ages that we happen to live in.

Thursday, December 24, 2015

Vanishing comments

All Blogger comments get emailed to me... and always wind up in my spam folder.

So I just go through the Blogger interface and approve all those that are not spam.

Except now I was looking in my mail spam folder, and I see comments in there that I never saw in Blogger! I don't know how this could happen, but it means some comments aren't appearing at all, and I have no idea why.

Especially, I saw Kevin Quinn and Prateek in my spam mail folder, but I can't find their comments anywhere in Blogger.

My apologies.

Wednesday, December 23, 2015

The Incoherence of "Non-Discrimination" as a Foundational Principle

'Things are made more complex still by the inclusion, in all European provisions, of “non-discrimination” as a human right. When offering a benefit, a contract of employment, a place in a college, or a bed in a hospital, you are commanded not to discriminate on grounds of…there then follows a list derived from the victims of recent history: race, ethnic group, religion, gender, sexual orientation, and whatever is next to be discovered. But all coherent societies are based on discrimination: A society is an “in-group,” however large and however hospitable to newcomers.' -- Roger Scruton

Liberals All


"What’s a liberal? Someone who 'respects . . . individual existence' so much that he 'attempt[s] to leave as much moral and political space around every human person as is compatible with the demands of social life.' Liberalism so understood is 'the official ideology of the Western world.' It is the ideology of 'the free, self-fulfilling individual,' which is equally at the foundation of the thought of Milton Friedman and Karl Marx. For the libertarian and the Marxist alike, utopia, when it arrives, will be marked by perfectly individualistic spontaneity or the immediate and unobsessive gratification of personal preferences without authoritative guidance from social or relational structures, without the limitations that used to be associated with birth, personal love, and death."

Tuesday, December 22, 2015

The Devil

Satan continually tempts me into cleverness as a substitute for wisdom. To cover his tracks, he whispers in my ear that the preceding sentence is just a metaphor.

Paradise waits

"These people would have us believe that everything is as it should be and that paradise is just around the corner: The paradise of a society whose idea of bliss is leisure, gadgets, and continuous fast displacement on concrete highways." -- Wilhelm Röpke, A Humane Economy, p. 37

What a pageant!

A friend of mine remarked on Facebook, about Miss Universe: "Holding a pageant to rank the worth of human beings in 2015: what a funny idea!"

I think he has actually offered a great characterization of progressive politics: A pageant to rank the worth of human beings. Whoever displays the most concern and guilt wins!

Saturday, December 19, 2015

Pas-ta Facts on the Left-Hand Side

Here: "[Pasta] was originally a failed Italian attempt to copy Chinese noodles..."

Sigh. Noah Smith apparently thinks "history" means whatever rumors he heard about the past when he was a kid. Because "Jeffrey Steingarten asserts that Arabs introduced pasta in the Emirate of Sicily in the ninth century, mentioning also that traces of pasta have been found in ancient Greece and that Jane Grigson believed the Marco Polo story to have originated in the 1920s or 30s in an advertisement for a Canadian spaghetti company."

So, something originating as a Canadian spaghetti ad is now a "fact" of the past... a.

As soon as someone calls something "reactionary"...

I stop listening:

"He adamantly refused to replace the primordial human distinction between good and evil with the pernicious ideological distinction between Progress and Reaction."

From a nice article here.

The "Problem" of Evil, II

"But I can easily imagine a world without evil! It would be perfect."

"No, it has a very grave defect: it is imaginary. No one can live and nothing can exist in an imaginary world!"

A world with only good and no evil may be like a world with only up and no down: purely impossible.

But until you can make your own universe, it is not appropriate to criticize someone else's!

Friday, December 18, 2015

The "Problem" of Evil

I don't really think there is such a problem. But I understand how worries about such a possible problem arise. And the best answer to those worries was written long ago:

Then the LORD answered Job out of the storm and said:

Who is this who darkens counsel
with words of ignorance?
Gird up your loins now, like a man;
I will question you, and you tell me the answers!
Where were you when I founded the earth?
Tell me, if you have understanding.
Who determined its size? Surely you know?
Who stretched out the measuring line for it?
Into what were its pedestals sunk,
and who laid its cornerstone,
While the morning stars sang together
and all the sons of God shouted for joy?
Who shut within doors the sea,
when it burst forth from the womb,
When I made the clouds its garment
and thick darkness its swaddling bands?
When I set limits for it
and fastened the bar of its door,
And said: Thus far shall you come but no farther,
and here shall your proud waves stop?
Have you ever in your lifetime commanded the morning
and shown the dawn its place
For taking hold of the ends of the earth,
till the wicked are shaken from it?

In other words, are you able to create a better universe without what you see as this one's "problems"?

Thursday, December 17, 2015

The Threat of "All White" Elite Colleges

A progressive friend recently wrote me and said, "If affirmative action is ended, America's elite colleges will again be all white."

First of all, let me note that I am fine with "limited" affirmative action: if there is basically a tie between two students seeking admission to a college, I think it is OK to use minority status to break the tie.

But what I really want to remark upon is the amazing claim that only affirmative action prevents America's elite universities from being "all white." UC Berkeley is a pretty elite place, and affirmative action is illegal in the California. Here are its most recent enrollment statistics.

Say what?! Whites make up only 24.3% of the admitted students! Chinese students are at 19.5%, nearly the same level as whites, and this despite the fact the whites outnumber Chinese in California by about 22 to 1. South Asians are another 9% of the admissions: over a third of the number of white admittees, despite whites outnumbering South Asians in the state by roughly 40 to 1. The numbers are similarly disproportianate for other Asian groups, for instance, Koreans are around 5% of admittees, despite being only about 1/80 of California's population.

As a "person of paleness," my reaction to these figures is, "Bully for you, Chinese and Indian and Korean students! And white students: you don't have any 'right' to be admitted as 40% (the white portion of the population of California) of UC Berkeley's students: You want to get in? Study harder!"

All that being said, blacks in the U.S. have, of course, had a unique history of being discriminated against. And I think it is fine to try to address this fact. But let's do it by devoting resources to getting more black students ready for elite universities, not by admitting those who aren't ready.

Atheism: An Evolutionary Disaster


“It is a great irony but evolution appears to discriminate against atheists and favour those with religious beliefs,” said Michael Blume, a researcher at the University of Jena in Germany who carried out the study. “Most societies or communities that have espoused atheistic beliefs have not survived more than a century.”

An Easy Fix for All Crimes!

I just saw a prominent libertarian posting on Facebook: "We can easily fix the problem of illegal immigrants by abolishing borders."

Yes, and we can "fix" the problem of trespassing by abolishing property lines. And we can "fix" the problem of theft by abolishing all property rights.

Wednesday, December 16, 2015

Some terrible arguments for raising the minimum wage...

Are on offer here.

First, try this on for size:
Those against raising the minimum wage often argue that it will hurt young people the most and that they “need the experience” of working at the minimum wage. But notice that the youth unemployment rate in Germany is 7.8 percent, and in Switzerland, it is 8.5 percent. In contrast, youth unemployment is 15.5 percent in the U.S., even though the U.S.’s minimum wage (using Purchasing Power Parities exchange rates) is below that of these Germany’s and Switzerland’s $10 and $9.20 an hour respectively. In other words, both have higher minimum wages, but much lower youth unemployment rates. Their overall unemployment rate is also lower: 4.5 percent and 3.4 percent, respectively. The minimum wage makes no difference on unemployment.
Now, if we want to be naive empiricists, we'd have to say that Komlos is clearly wrong. A higher minimum wage makes a big difference in unemployment: it makes it much lower! But Komlos doesn't say that. Why? Well, he would admit, there are other factors affecting unemployment besides the minimum wage. But once one admits that, the game is over, as the minimum wage opponent can claim that absent those very same factors  Komlos is acknowledging, unemployment would be much higher in Germany and Switzerland than in the United States.

The next baddie:
Another luminary contending for the spotlight, the Florida whippersnapper Marco Rubio, currently the third runner up, had the brilliant hypothesis that, “If you raise the minimum wage, you’re going to make people more expensive than a machine.” Cashiers are already being replaced by self-checkout machines, but people still need a living wage, Marco!
Actually, I don't really see anything being worth called an "argument" here at all: just some flippant mockery of Rubio. How is the fact that low-wage workers are already being replaced by machines supposed to undermine, rather than support, Rubio's argument?! And how is the fact that people "need" a living wage supposed to prevent their replacement by an automated burger flipper if that living wage is set too high?

I am all for helping poor Americans. But minimum wages are an attempt to do so on the cheap (no additional tax dollars needed), and are a crude, blunt attempt at that.

Instead, let's ensure that every American can have a decent life whether they have a salary or not, and then let employers and employees negotiate any wage agreements that suit both.

The scientists who ignored Miller's evidence for the ether were not just correct in retrospect...

they were correct at that time.

That is the point Michael Polanyi (and I following him) are making about Miller's experiments. To note that they were correct in retrospect presents no evidence for determining good scientific practice. Consider someone who in 1700 believed that there were planets beyond Saturn because in an opium trance he had a vision of some outer planets. Maybe this was a "true vision," or maybe not, but in any case, it was not a good scientific reason for holding the proposition. And that is not because it is a vision -- we will see that visions are what inspire great scientists -- but because it is not a vision offering a rational, scientific explanation of previously unexplained phenomena. And thus the fact that in retrospect, that person turned out to be correct says nothing about how scientists ought to proceed in practice.

The scientists who were presented with Miller's evidence in 1926 did not have the luxury of saying, "Well, let's wait until 2015 and see what the evidence says then." They had to make a decision about their research agenda in 1926, not in 2015: Were they going to continue searching for the ether, or were they going to assume that relativity is true? Polanyi's point is that they made the call based on the fact that relativity was offering a higher-level rational vision of the universe than they had before relativity, an explanation of phenomena that encompassed items that hitherto had just been "brute facts": much the same reasons that Galileo and Kepler committed to heliocentrism well before all contrary evidence was explained away. And these were the right calls at the time, whatever transpired later.

Great scientists are inspired by visions that reveal a more rational ordering of the universe than had previously been suspected. Those visions are not infallible -- e.g., see Kepler on the Platonic solids* -- and must ultimately be accepted or rejected based on evidence. But the beauty of the vision is sufficient scientific reason to follow it, and to ignore at least some contrary evidence for at least some period of time.

* Kepler's model of the solar system as based on Platonic solids:

Tuesday, December 15, 2015

The American View of the Irish, Circa 1870

Lest one think it was only in England we saw images like this, here is one from America, from a popular weekly:

The Difference Between Mises and Röpke

During the Second World War the city of Geneva had allocated garden plots along the line of the vanished city walls to citizens wishing to grow their own vegetables in a time of food shortages. This use of public land turned out to be popular; the city continued the allocation of plots after the war.

Röpke heartily approved of this undertaking, which both enabled people to obtain independently part of their own sustenance and provided the satisfaction of healthy achievement outside factory walls. When Ludwig von Mises came to visit Röpke at Geneva, Röpke took his guest to inspect those garden plots.

Mises sadly shook his head: “A very inefficient way of producing foodstuffs!”

“But perhaps a very efficient way of producing human happiness,” Röpke told him.
Perhaps needless to say, I am with Röpke here.

Our bizarre obsession with words

An English depiction of an Irishman.

Sitting in my landlord's backyard in England the subject of oats came up. I mentioned that there is a reason the Irish and Scots eat oats.

With great disdain in his voice, he remarked, "Well, the Irish eat oats because they're stupid!"

Then he looked at me in panic. I could see that, for the first time since I had known him, he had suddenly connected my last name with my ancestry. He immediately began trying to suck the words back into his mouth: "Of course, I'm joking! I'm joking!"

I smiled sardonically, and gave a little shrug. "Looks like rain tomorrow, hey?" I asked. The conversation moved on.

And if I wanted to obsess over such trivia, I could probably fill a notebook with hundreds of other "micro-aggressions" against my background: "You're Irish, so you must love to drink, right?" Wait a second, in fact, every St. Patrick's Day, I could walk around New York and record thousands of "micro-aggressions": "Ah, you're celebrating my heritage by getting drunk until you puke into the gutter! I see."

But really, come on: we live in a world where people are beheaded for the ethnicity or religion, where they are slaughtered in concentration camps for their ancestry, where they are blown up because they practice a different version of their religion from the people who blew them up. My ancestors lived as a subject population in their own land: they faced severe discrimination in ownership and voting rights, and were starved to death in vast numbers. These things, my friends, are macro-aggressions, worth complaining about. You know what micro-aggressions are? They are the little shit we should overlook, so we can try to get along peacefully.

Friday, December 11, 2015

Manners, not esotericism!

At the recommendation of a reader, I am reviewing Arthur M. Melzer's Philosophy between the Lines: The Lost History of Esoteric Writing (Chicago and London: University Of Chicago Press, 2014). Melzer is a Straussian who has latched onto Strauss's idea that philosophers commonly hid their "true doctrine" (their esoteric teaching) while giving lip service to common pieties. I must say that so far I find Melzer's case quite a stretch, as it seems to me he regularly interprets passages as evidence of esotericism that appear to have far more straight-forward readings.

For instance, Melzer quotes Erasmus criticizing Luther:

“For seeing that truth of itself has a bitter taste for most people, and that it is of itself a subversive thing to uproot what has long been commonly accepted, it would have been wiser to soften a naturally painful subject by the courtesy of one’s handing than to pile one cause of hatred on another…A prudent steward will husband the truth – to bring it out, I mean, when the business requires it, and bring it out so much as is requisite and bring out for every man what is appropriate for him – [but] Luther in this torrent of pamphlets has poured it all out at once, making everything public.”

Now, if I had run across this passage anywhere but in a book on esoteric writing, I would not have suspected for a single moment that such writing was what Erasmus was talking about! No, like a mother lecturing her teenager on criticizing all of Aunt Flora’s behavior in one go—better to “husband the truth… and bring it out so much as is requisite,” rather than give her the “bitter taste” of exposing all of her faults at once—what I would have thought was that Erasmus was lecturing Luther on was tact. And still, having encountered in a book on esoteric writing, I am still inclined to think Erasmus is talking about simple tact, and not esotericism at all.

The rationality of science

The great figures of the Scientific Revolution -- Galileo, Kepler, Newton -- were crystal clear on why science could be a rational enterprise: scientists were reading Nature, "the book of God"... and God being the supremely rational mind, naturally the book had a rational design, one that, with effort, our more limited minds could follow.

The major part of the history of the philosophy of science since the 18th-century has been the hunt to find some other, any other, basis for science's rationality. Once Hume destroyed the purely empiricist case for science, the search had an air of desperation to it. Instrumentalism, verificationism, falsificationism: all were attempts to patch up the whole Hume had noted.

All these attempts have failed.

Pundit = Shallow?

My friend Kenneth McIntyre takes apart David Brooks here. An excerpt:
The final question or concern is whether the book’s argument is ultimately unconvincing in the way that it is produced by Brooks. There is an old joke that there are two kinds of people in the world: those who classify the world into two kinds of people and those who don’t. Brooks is most definitely in the former class. We get the résumé virtues and the eulogy virtues, along with Adam I and Adam II. (Adam I prefers the résumé virtues.) There is a contrast between utilitarian logic and moral logic, which leaves the reader unclear whether Brooks is aware that utilitarianism is an actual theory of moral action. (He may not think that it is a convincing one—I don’t either—but utilitarians offer their theories not as alternatives to moral life but as accounts of moral life.) There are the cultures of self-effacement and self-promotion, which lead to the characters “Little Me” and “Big Me.” There is the party of reticence and the party of exposure. There are the people who see themselves as the center of the universe and the people who see themselves as part of the universe. There are the moral realists (like Brooks, of course) who see us as we are and moral romantics who believe that humans are naturally good. Finally, there are those who live for happiness (the bad people) and those who live for holiness (the good people). This quasi-Manichean reduction of everything to a good side and bad side is one of the least realistic accounts of moral life that I’ve ever read, and it certainly suggests that Brooks has his own romantic illusions about the moral life.

Thursday, December 10, 2015

Why scientists *cannot* "Revise what they know" in the face of every piece of adverse evidence

As Paul Feyerabend noted, all scientific theories are born falsified: at the very moment of their creation, there exist data that "falsifies" the theory. (See, for instance, Special Relativity and the Michelson-Morley experiment, or Copernican astronomy and the absence of visible stellar parallax.) But if the theory seems to solve enough other problems, and especially if it seems rationally satisfying, explaining a range of phenomena in an elegant manner, scientists will (correctly) ignore the "falsifying" data and plunge ahead using the theory, hoping that one day the recalcitrant data can be made to behave.

Wednesday, December 09, 2015

Einstein's special theory of relativity was "falsified" *thousands* of times

"But there yet remains an almost ludicrous part of the story to be told. The Michelson-Morley experiment of 1887... actually did not give the result required by relativity! It admittedly substantiated its authors' claim that the relative motion of the earth and the 'ether' did not exceed a quarter of the earth's orbital velocity. But the actually observed effect was not negligible; or has, at any rate, not been proved negligible up to this day... Moreover, an effect of the same magnitude was reproduced by D. C. Miller and his collaborators in a long series of experiments extending from 1902-1926, in which they repeated the Michaelson-Morley experiment with new, more accurate apparatus, many thousands of times." -- Michael Polanyi, Personal Knowledge, p. 12, emphasis mine

Polanyi notes that when Miller announced his results... the general community of scientists simply ignored him. They were already convinced that relativity was correct, and didn't care about its "falsification." And Polanyi contends they were quite correct to take this attitude.

Is there a theory that has been more thoroughly "falsified" than Popper's idea of "falsification" as the cornerstone of science?

Cosmos and Taxis call for papers

Jim Caton and I are editing a special Agent-Based Modeling issue of Cosmos and Taxis. Details are here.

Tuesday, December 08, 2015

Can "Shonk: The Movie" Be Far Off?

Here is a video of Shonk on hyperspheres, yet another media appearance which neglects to mention that he comments at this blog!

PS: Shonk, you win "Most Mathematician Outfit of 2015": we don't even have to wait for the rest of December!

Dynamic Medieval Science

From Thony:
Another point that Grant makes is that it’s very difficult to actually say what Aristotelian philosophy was as it changes constantly throughout the High Middle Ages. That Aristotelian Philosophy was some sort of unchanging, unchangeable monster cast in concrete by the Catholic Church with an injunction against all forms of inquiry is a myth perpetuated by people who believe in the Draper-White hypothesis of an eternal war between science and religion.

Let us look at a specific example of that process of change; in fact an area that would play a central role in the creation of modern science in the Early modern period, the laws of motion. Already in the sixth century CE John Philoponus criticised Aristotle theory of motion and introduced the concept of impetus. This stated that the thrower imparted a motive force to the thrown object, impetus, which decreases over time till the object stops moving. Via the Islamic thinker Nur ad-Din al-Bitruji in the twelfth century the theory was taken up and elaborated by Jean Buridan in the fourteenth century and through him entered mainstream Medieval thought. The theory of impetus played a central role in the early considerations of both Giambattista Benedetti and Galileo who developed the modern laws of fall. The seventeenth-century theory of inertia, Newton’s first law of motion is in reality a consequent development of the theory of impetus.

Also in the fourteenth century the so-called Oxford Calculatores developed mathematical quantified version of Aristotle’s theories, in particular deriving the mean speed theorem, which lies at the heart of the laws of fall. The Paris physicists took up this work and produced graphical representations of the mean speed theorem identical to the ones presented later by Galileo. To quote historian of mathematics, Clifford Truesdall:

The now published sources prove to us, beyond contention, that the main kinematical properties of uniform accelerated motion, still attributed to Galileo by the physics texts, were discovered and proved by scholars of Merton college…. In principle, the qualities of Greek physics were replaced, at least for motions, by the numerical quantities that have ruled Western science ever since. The work was quickly diffused into France, Italy, and other parts of Europe. Almost immediately, Giovanni di Casale and Nicole Oresme found how to represent the results by geometrical graphs, introducing the connection between geometry and the physical world that became a second characteristic habit of Western thought...
The last paragraph hits on an interesting point: science texts are generally just terrible on history. I think the problem is to some extent ideological, in that many of the writers want to believe the positivist story of science, but also is due to the fact that many people are not aware that historical facts are discovered by historians. So it is now "beyond contention" that advances still being attributed to Galileo were actually made in the 1300s: a newly discovered fact. I imagine that many writers of science textbooks think that historians start with facts and then weave "historical theories" around them, and so it wouldn't even occur to them that what was thought to be fact when they were in college has since been proven false.

Monday, December 07, 2015

Use your models, don't believe them!

Noah Smith complains:

"And to make it worse, most of the macro theories that economists take halfway seriously are too hard for intro kids, so they end up learning silly stuff like Mundell-Fleming and Keynesian Cross that no one even halfway believes."

But, believing is something one should never do with one's models: they are just models, and as abstractions are necessarily falsifications of the full reality being modeled. A road map is just lines on a piece of paper: it never follows each twist of a road, it doesn't show dangerous potholes, it doesn't let us know the road is now blocked by a slow-moving garbage truck. (Of course, interactive maps may show red dots when a road is backed up, but the basic point stands.)

This was a point we made when I was a partner in an asset-trading firm: our models were something we used, not believed, and as soon as they ceased to be useful, we abandoned them, and sought another useful model, without any silly concern about whether the new model was true.

And models can have many uses: they can help us make predictions, they can help us to isolate one factor operating in a complex situation, and they can help us to convey a certain view of the world.

When I teach macroeconomics, I use the Keynesian Cross for the latter purpose: I tell my students that the model is a highly simplified way of understanding what Keynesians believe goes on in a recession, and how they think we can get out of one. I stress that no one thinks that it captures even a tiny part of what goes on in a real economy. But, most of all, what I hope my students learn is what a model is, how to use it, and why it is necessarily limited.

The people in charge of Long-Term Capital Management apparently came to believe their model; why one should never do so can be seen here:

Sunday, December 06, 2015

The "Enlightenment"

"The term 'Enlightenment' is an ideological term with no utility in studying the structures of reality. But it has great utility in shutting off debate and preventing inquiry into questions about 'progress' or the roles and limitations of the natural sciences. It purports to describe that era when western civilization freed itself from the 'dark ages.'" -- Fritz Wagner

Friday, December 04, 2015

Tolkein's Trinity

"It seems that for Tolkien, the creation is envisaged in three stages—music, light, and being—corresponding in some way to the Father, the Son, and the Spirit. Yet the whole Trinity is involved in every stage, and the Logos or Word, who is the Second Person of the Holy Trinity, can justly be called the order, harmony and meaning of the cosmos, revealed to the Angels but only expressed in creation through the Breath of God." -- Christopher Morrissey, "The Six Days of Creation: Tolkien’s Account," quoting Stratford Caldecott

Pope Francis on Ideology

"In ideologies there is not Jesus: in his tenderness, his love, his meekness. And ideologies are rigid, always. Of every sign: rigid. And when a Christian becomes a disciple of the ideology, he has lost his faith: he is no longer a disciple of Jesus, he is a disciple of this attitude of thought."

Zeno for the computer age

If you wish to better understand Zeno's worry about the continuum, you could do worse than to consider loops in software. Case 1: You...