The man of system, on the contrary, is apt to be very wise in his own conceit; and is often so enamoured with the supposed beauty of his own ideal plan of government, that he cannot suffer the smallest deviation from any part of it. He goes on to establish it completely and in all its parts, without any regard either to the great interests, or to the strong prejudices which may oppose it. He seems to imagine that he can arrange the different members of a great society with as much ease as the hand arranges the different pieces upon a chess-board. He does not consider that the pieces upon the chess-board have no other principle of motion besides that which the hand impresses upon them; but that, in the great chess-board of human society, every single piece has a principle of motion of its own, altogether different from that which the legislature might chuse to impress upon it. If those two principles coincide and act in the same direction, the game of human society will go on easily and harmoniously, and is very likely to be happy and successful. If they are opposite or different, the game will go on miserably, and the society must be at all times in the highest degree of disorder. (TMS VI.II.42)
Smith contrasts the "man of system"--essentially a visionary who thinks he can shape society according to his vision of The Good--with a character of a much more subtle understanding of society, whom he discusses in the preceding paragraph:
The man whose public spirit is prompted altogether by humanity and benevolence, will respect the established powers and privileges even of individuals, and still more those of the great orders and societies, into which the state is divided. Though he should consider some of them as in some measure abusive, he will content himself with moderating, what he often cannot annihilate without great violence. When he cannot conquer the rooted prejudices of the people by reason and persuasion, he will not attempt to subdue them by force; but will religiously observe what, by Cicero, is justly called the divine maxim of Plato, never to use violence to his country no more than to his parents. He will accommodate, as well as he can, his public arrangements to the confirmed habits and prejudices of the people; and will remedy as well as he can, the inconveniencies which may flow from the want of those regulations which the people are averse to submit to. When he cannot establish the right, he will not disdain to ameliorate the wrong; but like Solon, when he cannot establish the best system of laws, he will endeavour to establish the best that the people can bear. (TMS VI.II.41)
It's a set of remarks that translates readily to a number of contexts. For example, Christopher J. Coyne introduces us to "The Man of the Humanitarian System" who thinks he can reconstruct societies according to his or her vision of The Good in his recent Doing Bad by Doing Good. In reading through The Wealth of Nations, I was struck by a passage with implications for those we might call "The Men and Women of the Moral System" who think that prohibition or high alcohol taxes are good ways to improve the moral standards of a community.
It deserves to be remarked too, that, if we consult experience, the cheapness of wine seems to be a cause, not of drunkenness, but of sobriety. The inhabitants of the wine countries are in general the soberest people in Europe; witness the Spainards, the Italians, and the inhabitants of the southern provinces of France. People are seldom guilty of excess in what is their daily fare. Nobody affects the character of liberality and good fellowship by being profuse of a liquor which is as cheap as small beer. On the contrary, in the countries which, either from excessive heat or cold, produce no grapes, and where wine consequently is dear and a rarity, drunkenness is a common vice, as among the northern nations, and all those who live between the tropics, the negroes, for example, on the coast of Guinea. When a French regiment comes from some of the northern provinces of France, where wine is somewhat dear, to be quartered in the southern, where it is very cheap, the soldiers, I have frequently heard it observed are at first debauched by the cheapness and novelty of good wine; but after a few months residence, the greater part of them become as sober as the rest of the inhabitants. Were the duties upon foreign wines, and the excises upon malt, beer, and ale to be taken away all at once, it might, in the same manner, occasion in Great Britain a pretty general and temporary drunkenness among the middling and inferior ranks of people, which would probably be soon followed by a permanent and almost universal sobriety. At present drunkenness is by no means the vice of people of fashion, or of those who can easily afford the most expensive liquors. A gentleman drunk with ale, has scarce ever been seen among us. The restraints upon the wine trade in Great Britain, besides, do not so much seem calculated to hinder the people from going, if I may say so, to the alehouse, as from going where they can buy the best and cheapest liquor. (WN IV.3.37)
In short, where alcohol consumption is part and parcel of day-to-day life, we perhaps see less drunkenness. As is well known by this point, prohibitions on different goods, services, or other activities feature lots of negative unintended consequences. The problem, perhaps, is not the price of booze per se but people's attitudes about it. Here's a volume published by the Institute of Economic Affairs titled Prohibitions. Here's Mark Thornton's book The Economics of Prohibition. In a July Featured Article, Benjamin Powell discusses the economics of prohibition.
Smith's contribution to economics was indeed path-breaking; he is not known as "the father of modern economics" for nothing. He offers much more, though, in his criticisms of those who wish to infringe on what he called "the obvious and simple system of natural liberty." Throughout his work, he shows us out things might not work out precisely the way we want them to.
This post is drawn from my notes for two projects on which I'm working; the first is a chapter (loosely) on Adam Smith's "Man of System," and the second is a book I'm writing with Deirdre McCloskey on the economic history of the last few centuries.