The Liebowitz and Margolis article only considers typing speed. On that basis, it finds a lack of evidence that Dvorak is significantly faster, and substantial evidence that it is only slightly faster (on the order of 5%). More importantly, the article claims that the costs of switching would likely wipe out any gains:

There are several versions of the claim that a switch to Dvorak would not be worthwhile. The strongest. which we do not make, is that Qwerty is proven to be the best imaginable keyboard. Neither can we claim that Dvorak is proven to be inferior to Qwerty. Our claim is that there is no scientifically acceptable evidence that Dvorak offers any real advantage over Qwerty.

However, the article makes no mention of accuracy or repetitive strain. It does claim that Dvorak typists move their fingers shorter distances, which would seem likely to reduce strain. In the absence of anything more substantial, I'll fall back on personal experience.

I switched from Qwerty to Dvorak 20 years ago on a bet, and have typed Dvorak ever since. I agree with the article's assessment that it isn't a whole lot faster, probably less than 10%. It's probably also slightly more accurate, but I'm really not sure. However, I am convinced that it is much easier on the fingers. I simply don't suffer from the strain I used to with Qwerty. When I Have had to be bilingual, as it were, at a client site (sometimes for weeks at a time), I have recovered my speed with Qwerty - and the increased strain along withi it.

Liebowitz and Margolis's article is motivated by an economic argument that market entrepreneurs will tend to converge on superior technologies and standards. I am not an economist: but I am a social scientist with some expertise in how innovation is socially shaped, and I don't buy their larger argument. As a scholar, I would point to Trevor Pinch and Weibe Bijker's classic work on the development of the bicycle, and philosopher Andrew Feenberg's assessment that technologies do not succeed because they are efficient: they are efficient because they succeed. One of the best examples of this that I know of is the IBM PC, which even as it took over the market was in many ways technically inferior to its competition.

A big problem I see with the Liebowitz and Margolis argument is that they assume typing speed is the measure of technical superiority. In reality, technical debates are often all about which criteria are relevant. It may well have been that when Qwerty and Dvorak were developed market actors also took for granted speed was the correct criterion. But this is precisely the kind of assumption that locks technology into path dependence. Is it more important to maximize speed, or to minimize stress and injury? There is no single objective answer to such questions. One can only claim market efficiency by assuming an answer. Saying "the aggregate choices of market actors decide" is circular logic that avoids the issue - in which case, the evidence Liebowitz and Morgolis present about speed is irrelevant anyway.

The key is comparing apples to apples i.e. not just comparing people doing the same job, but comparing people with the same number of years of full time experience of comparable quality.

A study that took into account education, hours worked, and skill into account found that:

Earnings are a function of skill and effort as well as gender. But even after we control for these factors, a relatively large earnings gap between men and women remains. The gender wage gap across the major creative class occupations ranges from $20,000-plus on the high end ($23,400 for management, $24,300 for law, and $26,600 for healthcare occupations ), to around $8,000-$10,000 on the low end ($8,700 for education, $9,800 for life, physical, and social science, and $9,900 for architecture and engineering).

Keep in mind that skill is not entirely an independent variable. People who are promoted to more resonsible positions have the opportunity to learn from the experience, whereas those who are not promoted don't. In other words, the effects of bias are likely to compound.

So the statistics above may understate the problem. The unadjusted numbers are truly horrendous. For law, men get paid more than twice as much ($138k vs $66k), which seems dramatically out of proportion to slightly more schooling (17.5 years vs 15.6 years) and a significant but not huge gap in hours worked (46.6 vs 40.9 hours - I don't know about you, but I personally find a dramatic drop-off in marginal productivity as hours increase).

Notice also the gap in education. Some comments here are suggesting that education is a domain of reverse descrimination, but that's not the story told by the wage gap.

I must echo the request of others here: if you have evidence to the contrary, plese provide it.

Agreed. Please don't break the existing content.

Science is based on the belief that there is a real world out there that has properties anyone can discover. What made this world "real" was that these properties did not depend on anybody's opinion, so you didn't have to give a damn about anybody else's opinion of your research either; you could discover the truth yourself, and be right even if everybody in the world disagreed with you.

Now we have social science. It's based on the belief that reality is defined by majority opinion. Naturally, one man's opinion is worthless, and only when a consensus is reached can you state that you know anything.

I'm afraid you completely misrepresent both science and what you call social science (but isn't). The problem is not whether the world is real: the problem is how can we know what these properties are.

Truth is not self-evident, as you imply. In fact, science does not produce "truths" at all: it produces theories. Scientists gather evidence and construct theories to explain the evidence. This is inductive reasoning: it can never be 100% certain.

Science isn't something "anyone" can do, as you imply: in many cases it takes a lifetime of expert training to be able to assess scientific evidence - and even then, there are honest disagreements and mistakes. Take your field of expertise. Can anyone make sound judgements? Is the common sense of the amateur dependable? I'll wager not.

So, we have scientists evaluating evidence, but they don't all agree. There is always evidence that doesn't quite fit. A scientific theory is never perfect. (If they did agree, if everything fit, then they would move on to something else because that particular problem would no longer be interesting!) With these scientistific experts disagreeing, how are we to decide who is correct?

Consensus. Communication. Agreement does not make things true in the world, but it is the best method we have for trying to judge whose truth is the right one. And it is imperfect.

You have fallen into two errors: First, of believing that once Truth is found that fact can be known and reliably communicated. Second, of believing that the only alternative is to believe nothing is true and reality is the invention of majority opinion. You are wrong on both counts.

Such misunderstandings lie at the root of anti-evolutionary belief, and sustain conviction that climate change science is a fraud. A non-expert believes he has found the one critical piece of evidence that disproves the consensus, and becomes convinced that this overturns the science. Science isn't calculus. It doesn't work like that.

The debate over evidence and whether it is possible to know Truth is an ancient one, reaching right back to Plato. One of the most important and influential scholarly works of the 20th century (and the source of the term "paradigm shift") is The Structure of Scientific Revolutions by Thomas Kuhn. I highly recommend reading the whole book: every scientist should read it. There is a pretty good recent overview at The Guardian, of all places. (Though the last bit about science being data- rather than theory-driven is bunk. It is both.)

As for social science, fifty years ago it was caught up in the belief that it could discover scientific laws of society akin to Newton's laws of physics. Then in the 1980s and 1990s there was a widespread rejection of this position, which in many cases resulted in an extreme postmodern rejection of science as a special way of acquiring knowledge. Thankfully, both extreme positions have now been widely rejected.

Scientists have an interest in continued funding. They are also in the best position to justify the work that they do. If you actually want to argue about whether these are good cuts are bad, you need to address the substantive arguments they make: not throw around sweeping generalizations.

Intelligent managament is about adjusting and reallocating, not cutting across the board. The programs you list are not all equivalent: not in net economic cost (or benefit), not in social cost (or benefit), not in terms of efficiency, or any number of other things. The idea that no one wants to give up anything so "everyone has to give up something" is ideological claptrap that tars some programs with the perceptions of others. (In any case, the easiest way to achieve it is to raise taxes.)

If you actually look at the context of these cuts in Canada, it's pretty clear that they are not all motivated by cost-savings. They coincide with elimination of the manditory long-form census, seriously damaging the government's ability to masure the impacts of social programs. There are huge cuts in environmental science, including climate change monitoring and a unique experimental lakes study area. The amounts involved are small, but the targets line up perfectly with the politics of a governing party that depicts environmentalists as terrorists and whose economic priority is oil exports. And as it happens, Canada - one of the countries under discussion - does not have "massive" debt - at least not compared to other OECD countries.

For a "blue skies" project, consider the packet switching research carried out in the late 1950s at the National Physics Laboratory in the U.K. The government decided that every project should have a "customer" with an application. Packet switching didn't. It was cut back. The U.S. invented the Internet.

I believe you are mistaken. From my reading of the article, the start date for the study has no impact on the results.

What they did was to take the global temperature record and various subsets of it (e.g. discarding urban measurements, adjusting for poor-quality measurement stations and so) and compare it to the record for various factors, such as volcanic eruptions, solar activity, and CO2 emissions, that could potentially affect temperature. Basically, they compared curves. They found a clear signal corresponding to volcanic eruptions, nothing measurable from solar cycles, and the best match by far was with CO2

Keep in mind that scientists do not measure global temperature: as different measurement stations go on- and offline and large areas of the Earth lack monitoring, that would be virtually impossible. This is why you never see claims that the global temperature used to be X, now it is Y. Instead, they measure changes in temperature. So if a given station measured Z degrees last year and Z' degrees this year, delta T = Z' - Z. That change can be compared with changes in measurements at other stations to get an overall fluctuation for a given time interval.

I am rather surprised you got modded down. I don't see any reason why you should have been. You are clear about your interpretation and the reasons for it.

Canadians already primarily use a card system called Interac to make most purchases; granted, it's been a while since I lived in Canada but even three years ago it was very rare for me to make a cash purchase.

I see no evidence that your experience is typical. Cash is widely used, as are credit cards. We are far from being a cashless society. I only use Interac a few times a year. Interac has been hit with fraud sprees by criminals using tampered skimmers. Unlike with credit cards, where banks impose such losses on merchants, banks often fail to refund the money.

This is absolutely correct for process patents. This is a requirements of the 1994 TRIPs (Trade-Related Aspects of Intellectual Property Rights) treaty. Here is the text of Article 34:

1. For the purposes of civil proceedings in respect of the infringement of the rights of the owner referred to in paragraph 1(b) of Article 28, if the subject matter of a patent is a process for obtaining a product, the judicial authorities shall have the authority to order the defendant to prove that the process to obtain an identical product is different from the patented process. Therefore, Members shall provide, in at least one of the following circumstances, that any identical product when produced without the consent of the patent owner shall, in the absence of proof to the contrary, be deemed to have been obtained by the patented process:

(a) if the product obtained by the patented process is new;

(b) if there is a substantial likelihood that the identical product was made by the process and the owner of the patent has been unable through reasonable efforts to determine the process actually used.

2. Any Member shall be free to provide that the burden of proof indicated in paragraph 1 shall be on the alleged infringer only if the condition referred to in subparagraph (a) is fulfilled or only if the condition referred to in subparagraph (b) is fulfilled.

3. In the adduction of proof to the contrary, the legitimate interests of defendants in protecting their manufacturing and business secrets shall be taken into account.

Whether this applies to software patents I am not sure (IANAL). As business process patents, it may, though it's not clear to me what the "product" would be. In any case, this is clearly the direction in which the law has been moving.

Ironically, by the way, negotiation that resulted in TRIPs was initiated by developing countries who found their economic development was being retarded by patents held by developed countries. Once the process started, however, it was hijacked by an unholy alliance of the pharmaceutical and entertainment industries. Poor countries were then effectively forced to join by developed countries, who withdrew from GATT leaving a choice between losing access to western markets and enacting onerous patent and copyright laws. Because of the impact on the cost of drugs for poor people, patents are a life-and-death issue. IP regulations, meanwhile, are expensive to implement, particularly in countries that lack the legal expertise:

the US Agency for International Development (USAID) now spends around a quarter of its annual budget on legal and regulatory training, including technical assistance from the US Patent and Trademark Office (USPTO), to help bring domestic legislation into compliance with TRIPs, including assessments of draft laws and recommendations regarding existing laws. (Christopher May and Susan K. Sell, Intellectual Property Rights: A Critical History, 2006

Your response to my comment are fair enough.

The worry about informal leaders may be trivial, but it's also relevant: it seems many people are willing to subscribe to the ideal of non-hierarchical decision-making. This was a legitimate concern about Occupy, for example (maybe it has been addressed?). In fact (and in contrast to common wisdom), flat hierarchies correspond to centralized power. The better models for direct democracy do not eliminate hierarchy, but they structure it to prevent the acquisition of privilege by individuals (e.g. through temporary positions and random assignment).

As a Canadian, I'm implicitly comparing the American system with ours. I guess that's a little parochial. In theory, their system seems to me better structured than what we have here. In Canada we have an unelected senate, leaders who rule with very little restraint, a foreign monarch as head of state, cities with no powers except those granted by the provinces, a constitution that is almost impossible to amend. At this moment in time some of these features may benefit us, blocking radical antidemocratic change, but in the long run I am doubtful. That our democracy seems more secure than theirs is probably less a result of good design than a result of historical contingency, such as the legacy of slavery, the scale of the country, and the effect of a variety of specific measures such as elected judges, large-scale gerrymanding, and the exclusion of third parties. Today, U.S. politicians venerate the constitution like a holy document while disregarding whatever bits they find inconvenient.

I agree with your criticism of the U.S. constitution. I should probably have called it "relatively good" rather than "excellent." Unfortunately, political institutions just about everywhere have been designed to limit actual democracy - and for this there is popular support! The masses do not trust the masses - but "the masses" is us! Between popular rule on the one hand, and technocratic rule on the other, we have neither: decent human beings though many of them are (at least in Canada), our politicians do not represent us, nor are they experts at much beyond persuasion. Technocratic rule descends into tyranny, so that leaves actual democracy. It's about time we had it.

Your critique of naive direct democracy - that leaders arise, but are informal and therefore not subject to safeguards - is an excellent one. But it's not enough.

Consider that the United States today suffers under exactly this scenario. Informal unelected elites have captured the levers of power to the point where the U.S. is not looking much like a democracy any more. This was accomplished despite the excellence of the design of the American system the strength of democratic principles among the American people - a citizenry still fairly engaged, and which was formerly also relatively well educated and informed.

Democracy is often present as the mechanism through which individuals, born citizens with their own preferences and interests, express and negotiate those preferences and interests, ideally with an eye to the common good. According to many advocates of direct democracy, this is wrong. We are not born citizens. It is not citizens who create democracy: rather it is the practice of democracy that creates citizens. We do not come to politics as individuals with already developed preferences and interests. It is by engaging with others in public discourse and debate that we learn to be citizens, to reason, to participate in public discourse, and through this process we discover and develop our preferences and interests. Democracy is thus a process of education. One of the great failings of representative democracy is that instead of treating us as active and evolving partners, it relegates us to the role of disengaged consumers who occasionally choose one option over another.

Yet realistically, even if we were to provide the perfect mechanism for people to participate, most of us, lacking interest and starved of time, wouldn't: with results like those you describe. One intriguing alternative draws on the jury system and the elections of ancient Athens. Decisions would be made not by professional politicians, but by randomly-selected groups of citizens with their range of private expertise. Such groups would be charged with investigating a particular issue for a period of time, after which they would disband.

I realize juries (chosen by counsel more for ignorance than independent thought) are typically reported as dysfunctional, and I don't doubt that this is so. Yet it only confirms that we do not know how to be citizens: and when it is demanded of us, we fail. Through failure, though, we can learn, and teach others. Forming a jury today, when virtually no one has substantial experience, amounts to throwing together a bunch of greenhorns and expecting them to spontaneously become experts.

For an idealized view of how a jury can teach its participants to be jurors, I suggest the film 12 Angry Men. I admit am not convinced of the wisdom of such a system. But if I was forced to choose, I would place my fate in the hands of a court rather than a politician. I would trust a random selection of my fellow citizens over a self-selected professional of politics. For with the crises we face today, our common fate is indeed the question.

That aside, if global catastrophe is such a big deal e.g. An asteroid is headed directly for Earth, every person is going to be affected in the same way therefore every person is equally responsible for dealing with it

You are wrong in fact and wrong in logic.

The impact of climate change is not equal. The poor live disproportionately in vulnerable areas. This is true not just for climate change, but for environmental disasters in general. It is mostly the poor, not the rich, who live on the deforested hillsides that collapse in landslides. It is mostly the poor, not the rich, who live in flood-prone areas. It is mostly the poor, not the rich, who make a living from dry and marginal soils susceptible to droubt. And it is the poor who lack the resources to cope when the water dries up, when food prices rise, when hit by torrential rains or brush fires. Global warming is not like an asteroid. It will not wipe out all life. But it will create great suffering, and that suffering will fall disproportionately on the poor. That is your error in fact.

Your error in logic is your claim of equal responsibility. If you and I are in a car crash, are we equally responsible because we both suffer the same loss? Even though I was speeding, talking on my cell phone and weaving in traffic while you were driving predictably and defensively, but were unable to avoid me when I suddenly swerved in front of you? Of course not. Responsibility results from the actions we take and the choices we make. We in the developed countries have produced most of the emissions and reaped most of the benefits. We are far more responsible for climate change than the peasants of India or Mexico or Bangladesh. Responsibility flows from actions, not consequences.

cyberpunk is not a libertarian utopia in the least

Oh, I agree! Utopia is not the only other choice (and I agree that cyberpunk has dystopian tendencies). In many ways it is very much like the world we live in. I'm not sure where your reference to libertarianism comes from. I would expect a libertarian "utopia" to be cruelly controlled by corporate elites - in that way I suppose cyberpunk fits the bill. Perhaps I was wrong to use the word "choice" given its association to rational choice theory and neoclassical economics. Libertarianism was certainly not in my mind. In Marcuse and Benjamin I'm quoting Marxists, after all. I could just as well have talked about action as Hannah Arendt uses the term, as a form of public citizenship through which we reveal and discover our differences.

The massive federation is overall peaceful because times are good and people don't have a reason to stir up shit. They aren't dissenting because their leaders are doing a good job. If you see that as impeding your personally freedom... Dude, you're straying into evil supervillian level ranting.

You have me chuckling pretty hard at the thought of me as a supervillain. Best insult evar. But I guess I'm not being clear. I think that people hold fundamentally different values that are valid but that can never be reconciled. Christian vs atheist, pro-life vs pro-choice, the pursuit of excellence vs the pursuit of equality. These can all be reasoned and honorable positions. Although I prefer the latter of each category, and believe it necessary to pursue such values vigorously through politics, I can respect the integrity and decency of many of those with whom I disagree (while also acknowledging the craven selfishness of many who are of like mind).

A free and democratic society will always have to deal with the tension and conflict between such sources of fundamental disagreement. Dissent is not something to be overcome: it is the condition of a healthy democratic society. A society without dissent is a society without democracy. This is actually the meaning of the word totalitarian. It does not simply mean dictatorship; it refers to a society that is like a unified organism, into which individual people fit like cells or organs, united in thought and purpose. Such a society might be peaceful, happy, wealthy, and well-governed (a possibility I sincerely doubt) - by restricting the ways in which its members could think, it might even have the appearance of democracy. But it could not be truly democratic or free.

To me the real tipping point seems to be as the "corporate dystopia" of which William Gibson and Cyberpunk was part.

At least not in my opinion. In classic dystopias like 1984 or Brave New World, there is virtually no space left for individual freedom and choice. Cyberpunk, however, is all about the spaces in between in which individuals can make choices and possibly change things. Philosopher Andrew Feenberg agrees:

The world Gibson describes is grim but not strictly speaking dystopian. It is true that elites rule it with immensely powerful means, but those means are so complex that they give rise to all sorts of phenomena over which no one really has control. There are many small openings through which a clever hacker can enter the system and commit a variety of unprogrammed deeds. The future is not clear but may yet be altered by human action on the network. (Alternative Modernity: The Technical Turn in Philosophy and Social Theory, 1995, p. 140)

The happy happy, joy joy world of Star Trek: The Next Generation, on the other hand, strikes me as truly static and dystopian. Nearly all cultural expression is centuries old. Every conflict can be solved through reason: there are no genuinely intractable differences of opinion or incompatible values among honest people. Only a totalitarian society could so thoroughly crush dissent and eliminate difference. I think I would go stark raving mad.

I believe a better future is possible and worth fighting for, but compared to ST:NG I'd rather have Gibson's grungy cyberpunk any day. It is dirty, flawed, corrupt - but also iredeemably human. Its diversity and vigor are resistant to the totalitarian disease. The tragedy is that cyberpunk came true: but now we seem to be passing out the other side. A cyberpunk world might be a let-down beside visions of the future we once thought we would enjoy, but compared to many genuine possibilities it's possitively upbeat. Take a look at the world of Paulo Bacigalupi's Windup Girl, for example (which despite its fantastic elements feels right in the same way that Neuromancer once did) - though even he leaves a small space for hope.

While I agree about the worth of utopian visians, I do not agree with the criticism of dystopian science fiction. The scholars of the Frankfurt School struggled to find an alternative to what they saw as a damaged society. When the human imagination limits itself to the realistic limitations of the world we live in, it serves to accept and conceal that world's flaws. Between the horrors of Stalinism and the alienation of capitalism, the Frankfurt scholars could not imagine an plausible alternative. So to find hope, they were deliberately negative. The injustices of the existing order pointed to the possibility of something better. Herbert Marcuse writes:

The critical theory of society possesses no concepts which could bridge the gap between the present and its future; holding no promise and showing no success, it remains negative. Thus it wants to remain loyal to those who, without hope, have given and give their life to the Great Refusal. At the beginning of the fascist era, Walter Benjamin wrote: It is only for the sake of those without hope that hope is given to us. (One Dimensional Man, 1964, p. 257)

So scientific truth is determined by taking a vote. Riight.

You confuse the hammer with the nail. Science is not truth: it is a method of accessing truth. With it, we construct models of reality, not reality itself. Reality is not determined by consensus - but good science is (hence science may be mistaken).

Rationality relies on us categorizing continuous physical phenomena into distinct categories. Such rationalization is never perfect: measurements suffer from error; theory and evidence never match up exactly. The problem remains: what is good evidence? Where exactly do we draw the line between one category and another? These are questions for human judgement. This is not relativism. There are better and worse answers, but no final ones.

Yes, Kuhn might be wrong (and Habermas, who also roots reason in communication) - but the question perfectly illustrates the point. How do we decide? Is there a foolproof scientific experiment that will resolve the question for all time? No: we are left with human reason, deliberation, and consensus. The consensus is that in significant ways he is right. Here is some of what he has to say about what he calls "normal science" (my argument is not concerned with his theory of revolutionary paradigm shifts):

No process yet disclosed by the historical study of scientific development at all resembles the methodological stereotype of falsification in direct comparison with nature. (p. 77)

anomalous experiences may not be identified with falsifying ones. Indeed, I doubt that the latter exist. . . . no theory ever solves all the puzzles with which it is confronted at a given time; nor are the solutions already achieved often perfect. On the contrary, it is just the incompleteness and imperfection of the existing data-theory fit that, at any time, define many of the puzzles that characterize normal science. If any and every failure to fit were ground for theory rejection, all theories ought to be rejected at all times. On the other hand, if only severe failure to fit justifies theory rejection, then the Popperians will require some criterion of "improbability" or of "degree of falsification". (pp. 146-7).

You accuse me of handing religion a victory against science. But if you credit science with objective access to truth you are only making it into its own religion - a truly grievous blow against science. At the heart of science is an understanding of its limitations. It is precisely by exaggerating science's perfectability and treating its ordinary imperfections as exceptional failures that its opponents discredit it, as has been the case with climate change.

(By the way, I have no interest in slandering religious folk. Though I am an atheist and do not share their faith, I remain a sceptic, and do not see why faith must always conflict with reason.)

science is not consensus based. One experiment is all it takes to create new insights, models, theories.

This is not true, although many scientists believe it. The idea of falsification was thoroughly debunked by Thomas Kuhn in The Structure of Scientific Revolutions half a century ago, now one of the most widely cited scholarly works. Kuhn is the originator of the term "paradigm shift."

Science is consensus based. We imagine that science compares theory with evidence, adjusting the theory to account for evidence that contradicts it. But in the final instance it is not and can never be objective: scientists must agree on what counts as good evidence, and there is no objective or scientific way to do that. It can only be done through communication and consensus. Kuhn writes, "Scientific knowledge, like language, is intrinsically the common property of a group or else nothing at all" (p. 210).

the solutions that satisfy him [the scientist] may not be merely personal but must instead be accepted as solutions by many. The group that shares them may not, however, be drawn at random from society as a whole, but is rather the well-defined community of the scientist's professional compeers. One of the strongest, if still unwritten, rules of scientific life is the prohibition of appeals to heads of state or to the populace at large in matters scientific. . . . The group's members, as individuals and by virtue of their shared training and experience, must be seen as the sole possessors of the rules of the game or of some equivalent basis for unequivocal judgements. (p. 168)

Thus scientists are notoriously poor at communicating their research to the public - because being a scientist means only respecting the scientific views of other scientists. Some people react emotionally to the tone of science, feeling that scientists talk down to them as ignorant outsiders. Guess what? They do - because we are. I can accept that: as someone with some measure of expertise in a few areas, I can appreciate the years of study and experience required to develop expertise in others.

But where does this leave us? Is science simply a game of popularity and politics? Of course not. Science works, it works very well - and it works by consensus. This does not undermine the claims of climate science: it underlines consensus-based science as the best method we've got. To deny the importance of consensus is to throw the baby out with the bath water. If you reject the consensus of scientists about climate change, your only recourse is to appeal to some other consensus. I'll take the consensus the scientists, thank you very much.

[*] Quotes from Thomas S. Kuhn, The Structure of Scientific Revolutions 2nd ed, University of Chicago Press, 1970.