Luxury is always proportionate to the inequality of fortunes. If wealth is equally shared within a state, there will be no luxury, for it is based solely on the conveniences which one affords oneself through the work of others.
For wealth to remain equally shared, the law must allot to everyone no more than the physical necessities. If anyone has more, some will spend, others will acquire, and inequality will set in.
If we suppose physical necessities equal to a given sum, the luxury of those who have only the necessities will equal zero ; he who has twice as much will possess luxury equal to one ; he who has double the assets of the latter will possess luxury equal to three ; twice as much again will yield luxury equal to seven, in such a way that, the wealth of the following person still assumed to be twice that of his predecessor, luxury will grow by a factor of two plus one, in this progression : 0, 1, 3, 7, 15, 31, 63, 127.
In Plato’s Republic luxury could have been exactly calculated. There were four kinds of cens established.  The first was precisely the limit where poverty ended, the second was double the first, the third triple, the fourth quadruple. In the first cens, luxury was equal to zero ; it was equal to one in the second, to two in the third, to three in the fourth ; and it thus followed the arithmetic proportion.
Considering the luxury of various peoples with respect to each other, in each state it is in compound proportion to the inequality of fortunes among the citizens and the inequality of wealth of the various states. In Poland, for example, there is an extreme inequality of fortunes, but the poverty of the whole prevents there being as much luxury as in a wealthier state.
Luxury is again proportionate to the size of cities and especially of the capital, so it is in compound proportion to the wealth of the state, the inequality of private fortunes, and the number of men assembled in certain places.
The more men there are together, the more vain they are and the more they feel rising inside them the desire to stand out in small things.  If they are in such great number that most are unknown to each other, the desire to distinguish oneself doubles, because there is more expectation of succeeding. Luxury gives this expectation ; everyone adopts the signs of the station above his own. But by dint of wanting to distinguish himself, all become equal, and no one any longer stands out ; since everyone wants to make people look, no one attracts any notice.
There results from all this an overall disadvantage. Those who excel in a profession place on their art the price they wish ; the smallest talents follow that example ; needs and means are no longer commensurate. When I am forced to sue, I must be able pay a lawyer ; when I am ill, I must be able to have a physician.
Some have thought that the gathering of so many people into a capital diminished trade, because men are no longer separated by a certain distance. I do not think so : people have more desires, more needs, and more whims when they are together.