Is the Corruption of Congress an Inevitable Consequence of Division of Labor?

Adam Ferguson, in An Essay on the History of Civil Society (1767), analyzes the effects of division of labor ('separation of arts') on society in general, and here on the conduct of deliberative bodies:

The principal objections, to democratical or popular government, are taken from the inequalities which arise among men in the result of commercial arts. And it must be confessed, that popular assemblies, when composed of men whose dispositions are sordid, and whose ordinary applications are illiberal, however they may be intrusted with the choice of their masters and leaders, are certainly, in their own persons, unfit to command. How can he who has confined his views to his own subsistence or preservation, be intrusted with the conduct of nations? Such men, when admitted to deliberate on matters of state, bring to its councils confusion and tumult, or servility and corruption; and seldom suffer it to repose from ruinous factions, or the effect of resolutions ill formed or ill conducted.

The Athenians retained their popular government under all these defects. The mechanic was obliged, under a penalty, to appear in the public market-place, and to hear debates on the subjects of war and of peace. He was tempted by pecuniary rewards, to attend on the trial of civil and criminal causes. But, notwithstanding an exercise tending so much to cultivate their talents, the indigent came always with minds intent upon profit, or with the habits of an illiberal calling. Sunk under the sense of their personal disparity and weakness, they were ready to resign themselves entirely to the influence of some popular leader, who flattered their passions, and wrought on their fears; or, actuated by envy, they were ready to banish from the state whomsoever was respectable and eminent in the superior order of citizens; and whether from their neglect of the public at one time, or their mal-administration at another, the sovereignty was every moment ready to drop from their hands.

The people, in this case, are, in fact, frequently governed by one, or a few, who know how to conduct them. Pericles possessed a species of princely authority at Athens; Crassus, Pompey, and Caesar, either jointly or successively, possessed for a considerable period the sovereign direction at Rome.

Whether in great or in small states, democracy is preserved with difficulty, under the disparities of condition, and the unequal cultivation of the mind, which attend the variety of pursuits, and applications, that separate mankind in the advanced state of commercial arts. In this, however, we do but plead against the form of democracy, after the principle is removed; and see the absurdity of pretensions to equal influence and consideration, after the characters of men have ceased to be similar.