"The 'man of system' 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 the chess-board; he does not consider that, in the great chess-board of human society, every single piece has a principle of motion of its own." QotD

“The statesman, who should attempt to direct private people in what manner they ought to employ their capitals, would not only load himself with a most unnecessary attention, but assume an authority which can safely to trusted, not only to no single person, but to no council or senate whatever, and which would never be so dangerous as in the hands of a man who had the folly and presumption enough to fancy himself fit to exercise it.” 
    "[This] man of system ... 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 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 the chess-board; he does not consider that the pieces on 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 choose to impress upon it . . . It is to fancy himself the only wise and worthy man in the commonwealth, and that his fellow-citizens should accommodate themselves to him, and not he to them.”
          ~ Adam Smith, from his Wealth of Nations and Theory of Moral Sentiments

[Hat tip Richard Ebeling, from his article 'Milton Friedman and the New Attack on Freedom to Choose']