Take a phil class featuring Frege, Russell, the early Wittgenstein, Tarski, Carnap, Reichenbach, and the other logical positivists; or classes in formal / symbolic logic; or philosophy of mind classes at the intersection with AI.

Well, I'll quit after one more try. The philosophers you are talking about, unless they're incompetent, know all the things you are saying. Exactly the issues you are raising have been a standard area of philosophy for about a century and are part of almost everyone's early training, but you're speaking as though this was a great discovery of yours.  
 
I don't know what the source of your unhappy experience was -- presumably an undergrad class or a book you read -- but the conclusions you have drawn from your data point are worthless. There may have been a real problem with the particular expression of the example you gave -- I'm not sure even of that -- but it doesn't impact philosophy in general. You have chosen to attack philosophy at one of its strong points, and you would not have done that if you had known what you were talking about.

Razib, I think that the takeover of economics by physicists around 1940 or 1950 was a very mixed success. For one thing, they weren't very good physicists. They're just now finding out about "long tails", etc., which (Cosma Shalizi and others tell me) physicists have know about since 1900 or 1930. The systems they described were unnaturally regular.

I do not like today's analytic philosophy, but the things that Frege, Russell, the logical positivists, Tarski, et al were doing around 1900 -- 1950 were necessary precursors of IT and AI and made enormous contributions. And a lot of it as word-game type stuff. 
 
Eoin, that doesn't fly. You solved the verbal problem without solving the logical problem it was trying to express. That means either that the logical problem was not expressed well, or that you missed the point of what was going on. In fact, the philosophers who use that kind of story problem are often the same ones who do develop the kind of formal ways of making unambiguous statements that you want.  
 
I'm sorry that you did poorly in your philosophy class. But I can tell you that it's very unusual for me to say anything good about analytic philosophy, but you made me do it.

There's a lot more to making a good verbal argument than following grammar or writing with an OK style. That's the bare minimum for getting anyone to read your stuff, and it's not a hard standard to reach. Verbal arguments are still criticized on various other grounds, and the example you gave would be quickly rejected as empirically false.  
 
Yet, I am pretty sure than analytical writing means, first and foremost, good writing, 
 
No, it doesn't. 
 
The inarticulate defense of the truth will get an F, while the articulate defense of the untrue, or obscure, an A. 
 
You're right about "inarticulate", because if you just assert a truth without giving reasons why it is true, you're not doing anything. It's the same in science -- right answers without scientific backing don't count. 
 
I am really talking about high level philosophy. 
 
Oh, come on.  
 
As for Marx, he's hardly a typical philosopher. Some of the things he said were true, and economists since then (including capitalist philosophers) have had to deal with them. Some were not true. The same is true of scientists. None of them are right all the time.

My problem with philosophers is that they're plenty analytical, but not very empirical, and that they tend to solve problems by narrowing them, so that they get a good answer within their way of formulating the question that doesn't necessarily apply to any actuality. But I've been assured by people in AI and related areas of linguistics and psychology that philosophers are players in those fields, and I started out thinking that they were just tagalongs and copycats.  
 
Quibbling about subtleties and abstruse questions in logic, etc. has been very productive in philosophy / logic / systems theory / information theory / game theory etc. It's often or usually possible to find a commonsense normal-language solution, as with the Baggini problem, but that doesn't mean that working on these problems is pointless. I do think that philosophers spend too much time on weird hypotheticals, but you shouldn't be sure that arguments are pointless. (I remember that when I first read about Boolean algebra 46 years ago, my immediate reactions was "Who cares?") 
 
the falling of a cliff example makes no sense.

It's an interesting chart. Probably it is skewed by non-native speakers in engineering. The more applied fields tend to rank low, even including medicine. (Seemingly RN and MD are lumped, but in my experience science PhDs who teach med students tend to be unimpressed). I'm pretty sure that "Humanities & Arts - other", the highest Humanities quantitatively, is mostly linguistics.  
 
The chart was obviously prepared by a philosopher. Philosophers suffer worse tunnel vision even than economists, so I'd say that the GRE misses something.

I think that it's worth asking why the settlement of the northern forests proceeded slowly, but I don't think that technical difficulty was the main reason. Various combinations of undermining, cutting, and fire can do the job, and timber has its value. Perhaps the drain of population toward the imperial south had something to do with it. And certainly the easily-farmed areas were farmed first.

I don't understand the mystery about clearing land. During the years between 1 AD and 1000 AD a lot of land was cleared. Cut trees can be used for firewood or for lumber. I imagine that the absence of steel axes is what people are talking about, but that's not an unsurmountable difficulty.

Curious, that would account for a very rapid population change for a people which had suddenly access to milk. If the intolerant children were unhealthier and the tolerant children better nourished (because of a new food source), selection would be quite rapid. There might be no increase in fertility or even a decrease, but the ones who lived would mostly be the tolerant ones.

That's not what I said. A genetic marker, not a cause of much of anything. If the Japanese are drinking milk, how horrible can it be? And effects on individuals seem variable. You can't say "People X doesn't raise cattle because they're lactose-intolerant". More, "People X haven't been raising cattle, so they're lactose-intolerant."

Wrong thread.

Note that I correctly described my fiscal acumen, however.

I'm already not sure of the "very rarely drink fresh milk" part. But without refrigeration, they're sure to consume mostly non-fresh products.

The Malthusian trap is probably mostly heavily-taxed land-poor peasants who can't escape the land (even if formally free) just because there's no open land. Pastoral populations anywhere (regardless of ecology) are probably better fed and less dense, but in defensible places good for agriculture, peasant agriculture eventually take over, as happened in France, Germany, and Britain between 1 AD and 1000 AD.  
 
There are ways of processing milk to reduce the lactose load (souring and fermenting). I haven't seen this discussed and don't know what its significance is. Mongols rely as heavily on milk products as any people today, though as East Asians they'd be expected to be intolerant.  
 
The kinds of "spoilage" that supposedly make milk impractical in warm climates also reduce lactose load, and some African peoples raise cattle. Mongols very rarely drink fresh milk; mostly what we'd call yogurt, buttermilk, and cheese, as well as a zero-lactose weakly-alcoholic milk product called kumiss. 
 
Since all infants are lactose tolerant, lactose intolerance must be a fairly simple switch which is easy to turn back. I've also read that babies who are weaned to cows milk instead of away from milk entirely keep their tolerance. Japan has an indigenous dairy industry and milk consumption was increasing up to a point. I'm starting to think of lactose intolerance more as a marker and less as a cause. 
 
There are a lot of factual assumptions in this post, and I'm not sure of all of them. I'm putting this up for discussion.

My citations of Heather above dropped this clause: the lack of tax base meaning that the conquest wouldn't have been self-supporting. 
 
This is critical: conquest wouldn't have been self-supporting in large part because of cost of defending the territory, especially distant territory. An easily-defensible area no more productive than Germany could be self-supporting.  
 
Sorry for a garbled post.

Lactose: when all the arable land is in use, there will be minimal stockraising, but before saturation marginal land might be left to livestock. 
 
It may be that the small populations in these under-utilized areas are better fed, for Malthusian reasons.

I'd actually see three axes here. One, W to E, as stated. Two, distance from the Mediterranean and attached seas (rather than N to S) -- the poorest northern provinces are inland provinces, whereas if there had been inland provinces in Africa I suspect that they'd have been poor too. Third, northeast to south center, showing vulnerability to steppe attack (Dalmatia and Moesia, which are southern and on the sea, but under attack.) 
 
So the western pole explains Numidia and Mauretania. The inland pole and the Western pole explain Gaul and maybe Germany.The steppe pole explains the whole contested area west of Anatolia. (Germany suffers from all three.)

In Peter Heather's The Fall of the Roman Empire the argument is also made that expansion beyond the Rhine did not occur mostly because of the poverty of the lands. 
 
This can be generalized to the steppe. It is said that the steppe was pastoral because it was too arid to sustain agriculture, but this is not true. The Ukraine is a bread-basket, and this was true during classical times, when the Scythians exported grain to Greece. 
 
Because of their greater mobility, and because they have no fixed capital to defend, small nomad groups have an immediate advantage over much larger agrarian peoples: they can concentrate their attack on one point quicker than the defenders can reinforce it, and don't need to defend their rear, whereas the defenders have to defend every point on their line of defense. (On the other hand, for logistic reasons pure steppe cultures can't manage a sustained attack. 
 
On the steppe, without natural defenses (mountains, seas) and with an abundance of grazing land for horses,offensive warfare has a natural advantage over defensive warfare. So during many periods the Ukraine reverted to pasture, because while it was agriculturally productive, it was not productive enough to defend itself against nomad cavalry, given the offensive advantages there. Even the most productive agrarian civilizations, with natural defenses and large areas of densely productive agriculture, had difficulty defending themselves against the nomads. Outlying agricultural areas were impossible to defend. 
 
Economic-determinist theories of history (e.g. Engels') tend to misunderstand this kind of military relationship -- a very poor, underpopulated, economically unproductive steppe society can challenge a very wealthy sedentary society because of these military relationships.  
 
Or, in short, the steppe's lack of means of production is historically (politically and militarily) counterbalanced by their wealth of means of destruction.

I've encountered the reevaluation and I find it initially very unconvincing. For one thing, I'm pretty sure that there was a population decrease and a decrease in trade after about 550 AD which only gradually was recouped by about 800. (Those aren't exact dates at all). The Gothic, Frankish and Lombard kingdoms did claim to be heirs of Rome, and they did try, but they didn't do a very good job of it.  
 
It's hard to exaggerate the poverty of the literature 600-800 AD. I spent awhile looking at it in translation, and it's almost all chronicles of a very crude sort, law codes, and very unoriginal encyclopediac summaries of past scholarship. Part of the problem may be that the Germanic literature was later destroyed by monks; "Beowulf" is the sole long survivor of what presumably had been an extensive body of work. (Charlemagne supposedly took steps to preserve the old Frankish songs, but nothing survived of that.) 
 
One oddity is that in Ireland, outside both the German and Roman rule, literature seems to have flourished.