I like the final paragraph:
"Critics of capitalism used to cite Joseph Schumpeter and Daniel Bell to show that the free market is ultimately undermined by its own successes: the wealth the work ethic creates makes people want to work less. The welfare state has its cultural contradictions, too. It rests on consensus, which is another way of saying a lack of cultural variety. The stronger the consensus, the more room a welfare state has to grow. But as consensus strengthens, so does a certain naïveté, a belief that your own idiosyncratic habits are something that no one else could fail to find irresistibly seductive. Sweden's biggest immigration problem may be a matter not of crime, unemployment and Islamic radicalism but of something else altogether: that its newcomers understand perfectly well what this system erected in the name of equality is and have decided it doesn't particularly suit them.
Maybe yes, or maybe not. It depends on how the wealth is distributed, sometimes the decadence affects the elites/the rich more. See my tagline.
In long lasting societies the rich were constrained by the strong religious rules and duty of military service (like medieval knighthood) while the working classes were kept poor and toiling.
Machiavelli provides interesting comments on the dangers of prosperity and how to deal with it:
The builders of Cities are free when any people either under a Prince or by themselves are constrained either by pestilence or by famine or by war to abandon their native country, and seek new homes: These either inhabit the cities that they find in the countries they acquire, as Moses did, or they build new ones, as Eneas did. This is a case where the virtu and fortune of the builder of the edifice is recognized, which is of greater or less wonder according as that man who was the beginner was of greater or less virtu. The virtu of whom is recognized in two ways: the first is in the selection of the site, the other in the establishment of the laws. And because men work either from necessity or from choice: and because it is seen here that virtu is greater where choice has less authority (results from necessity), it is (something) to be considered whether it would be better for the building of a city to select sterile places, so that men constrained to be industrious and less occupied with idleness, should live more united, where, because of the poverty of the site, they should have less cause for discord, as happened at Ragusa and in many other cities built in similar places; which selection would without doubt be more wise and more useful if men would be content to live of their own (possessions), and not want to seek to command that of others.
However, as men are not able to make themselves secure except through power, it is necessary to avoid this sterility of country and locate it in very fertile places, where because of the fertility of the site, it can grow, can defend itself from whoever should assault it, and suppress whoever should oppose its aggrandizement. And as to that idleness which the site should encourage, it ought to be arranged that in that necessity the laws should constrain them (to work) where the site does not constrain them (does not do so), and to imitate those who have been wise and have lived in most amenable and most fertile countries, which are apt to making men idle and unable to exercise any virtu: that to obviate those which the amenity of the country may cause through idleness, they imposed the necessity of exercise on those who were to be soldiers: of a kind that, because of such orders, they became better soldiers than (men) in those countries where nature has been harsh and sterile: among which was the Kingdom of Egypt, which notwithstanding that the country was most amenable, that necessity ordained by the laws was so great, that most excellent men resulted therefrom: and if their names had not been extinguished by antiquity, it would be seen that they would have merited more praise than Alexander the Great, and many others of whom memory is still fresh.
And whoever had considered the Kingdom of Soldan and the order of the Mamelukes, and of their military (organization) before it was destroyed by Selim the Grand Turk, would have seen there how much the soldiers exercised, and in fact would have known how much they feared that idleness to which the benignity of the country could lead them if they had not obviated it by the strongest laws. I say therefore that the selection of a fertile location in establishing (a city) is more prudent when (the results) of that fertility can be restricted within given limits by laws.
(Discourses, book one, chapter I)