Disregarding some variance from state to state, the three estates consisted of (a) Clergy (b) Royalty/Nobility and (c) Commoners. The so-called fourth estate was the peasantry. The modern analog to these estates would be (a) churches (b) the political and regulatory apparatus and (c) business folk. Peasants would be sort of like working folk. Since this is chiefly a look at civil society, I'll leave off parsing the military for now, but I think it might be interesting to return to it in another post. What I do want to consider is how each estate uses coercion and how this use changes when they combine forces.
One way to model the rise of the state is to start with a disorganized rabble of undistinguished humans, preying on each other in a Hobbesian war of all-against-all. By dint of natural talent and perhaps a bit of luck, champions arise and convert the surplus they extract from their fellows into elite positions. If you're good at telling stories and threatening folks using psychology, the first estate might suit you. If your talent is chiefly the ability to extract wealth using physical violence and threats to that effect, you might consider a career in the second estate. If you've an adept hand with arranging the affairs of business and a keen eye for the disposition of tradeables, look to the third estate for your fortunes.
Before I continue, I think I should share an important caveat: there is no a priori reason to claim that any of these roles need necessarily be maladaptive nor is there reason to claim any estate purely beneficent. People inhabit offices and they are as they are. 'Tis the nature of the office and the rules which govern its disposition that either charge or muzzle the characteristics of the holder. History is rife with examples of cruel despots and benevolent rulers alike. Yes, the world did suffer the corruption of the Borgias, but I think Peter was a pretty cool guy. Eh was the rock and didn't afraid of anything. The third estate might be a bit harder to nail down, since many of the examples of their poor behavior is tied closely to untoward allegiances with state authority. It becomes harder to disentangle who really is the bad guy when talking about Enron or the East India Company or Archer Daniels Midland. Still, there's no pat black-and-white tale of heroes and villains when discussing large institutions, only individuals, motivations and rules.
Prior to the close of the Manorial Era and the rise of The Enlightenment (give or take a few hundred years here or there*), the crown had the swords and the church had the fear of the afterlife. Alternatively, the chief had the spears and the shaman had the spirits. This meant that the temporal authority could threaten you here and now and the spiritual authority could threaten you in the afterlife. Combined, this is a full court press (I don't actually know what that means; I'm not much of a baseball fan). Accordingly when these institutions were dominant, we'd see rents extracted by way of taxation and tithe. Again, I stress that this is not to condemn any particular institution. In a plausible counterfactual state of the world, things might have been much worse. As Adam Smith noted, in so many words, as long as there was peace, easy taxes and a tolerable administration of justice, things would be good enough for the third estate that they could go about their business of voluntary (and sometimes euvoluntary) trade, making the world incrementally opulent.
Then something shifted. Deidre McCloskey believes it was the rise of what she calls "bourgeois dignity", where the relative status of the third estate improved. It was also (perhaps coincidentally?) marked by a waning of Royal power in England (The Glorious Revolution) and some knocks to the Roman Catholic Church thanks to Henry VIII and Martin Luther. Partitioned by political geography, competition in the first and second estates increased a little. With William and Mary, the crown now had to share power with Parliament a bit more. With the rise of Lutheranism, Rome lost the hook of selling indulgences. And of the third estate? Well, 1623 saw the start of monopoly rights granted by a beleaguered James I, monarch during the Gunpowder Plot. These rights really got going under progressively weaker rulers until we see craziness like the South Sea Company or the British occupation of India. The logic is pretty obvious: the crown has to protect its investment, right? How do political elites protect stuff? Guns. Pretty simple. At any rate, we see the obverse of what happens in the first two estates: the political elites sort of relax (slowly and fitfully) their partnership with the Church and tighten their partnership with business elites.
At least, that's one way to look at it. We got sort of a good competition thing going between sects of Christianity and shut down corrupt peddlers selling pilfered human remains labeled as the fingerbones of dead saints. England ousted James II (affectionately known as James the Shit) and ushered in William the Orange, whose reign saw the birth of modern finance (arguably). Meanwhile, commerce attracted finer and finer minds, now bent to the tasks of innovation and trade rather than rote canon or ecclesiastical rumination. Breaking the throttle-hold of elite privilege unshackled economic growth. Pretty cool, man.
Of course, as long as there are elites, there's a temptation to circle them wagons and, uh, divert the sluice-box of the chuck stew or something... yeah, I'm not much of a cowboy either. Point is, if there's an advantage to be gained by sharing coercive power, and knowing that people are always and everywhere people, it should come as no surprise when people take advantage. Regulatory authority has replaced the Divine Right of Kings as the elite partnership of choice for extracting rents.
So what can we imply from any of this? Well, we see that religions that had previously sponsored atrocities like the Children's Crusade are now primarily humanitarian organizations only. That's cool, very cool indeed. We also see that states that have competing political elites tend on average to do better (which may be reason to be wary of the consolidation of executive power) and we see that good business competition under a tolerable administration of justice fares pretty tootin' good compared to control by capricious outsiders. Each step in the direction of more competition in each estate tracks pretty well with more (directional) euvoluntarism, by crown, by cross or by distaff. Similarly, we see that partnerships between the estates can increase coercion and reduce euvoluntarism. When regulation regulates, that can be tolerable justice. When regulators protect against competition, well Andy, that's another kettle of fish. I hope that folks pick up on this and do what they can to try to push for more euvoluntarity, even if it's just incremental. I have a feeling the resistance is more implacable than most folks realize.
*yes, I am playing fast and loose with history here, but it's not crystal clear when the dominant coalition shifted