A sabedoria de John Maynard Keynes

"But the principles of laissez-faire have had other allies besides economic textbooks. It must be admitted that they have been confirmed in the minds of sound thinkers and the reasonable public by the poor quality of the opponent proposals - protectionism on one hand, and Marxian socialism on the other. Yet these doctrines are both characterised, not only or chiefly by their infringing the general presumption in favour of laissez-faire, but by mere logical fallacy. Both are examples of poor thinking, of inability to analyse a process and follow it out to its conclusion. The arguments against them, though reinforced by the principle of laissez-faire, do not strictly require it. Of the two, protectionism is at least plausible, and the forces making for its popularity are nothing to wonder at. But Marxian socialism must always remain a portent to the historians of opinion - how a doctrine so illogical and so dull can have exercised so powerful and enduring an influence over the minds of men and, through them, the events of history. At any rate, the obvious scientific deficiencies of these two schools greatly contributed to the prestige and authority of nineteenth-century laissez-faire."