In the afterword to his magisterial Battle Cry of Freedom (which I finished reading over Christmas), historian James McPherson says that the Civil War was a turning point between two different understandings of liberty. He distinguishes them using the terms made famous by Isaiah Berlin: “negative” liberty and “positive” liberty. Roughly, negative liberty is freedom from external interference–the “right to be left alone.” So understood, freedom is essentially opposite to government power: the stronger the government, the less freedom. The American Revolution was arguably a battle for negative liberty in that the colonies were seeking freedom from English domination and that the resulting government was one of sharply limited powers.
By contrast, positive liberty is having the actual capability to do something you want. Freedom in this sense is not inherently opposed to power, but in fact requires a strong government. Freeing slaves, to take the most salient example, required a dramatic increase in federal power.
McPherson contends that, after the Civil War, positive liberty became the dominant American understanding of freedom. He points out that the first ten amendments to the Constitution–the Bill of Rights–were essentially a series of “thou shalt nots” directed at the federal government intended to limit its power; but the post-Civil War amendments (the 13th, 14th, and 15th) established that the federal government did have the power to enforce the equal civil rights and freedoms of citizens. This created a much wider scope for government activity to ensure equal effective freedom.
McPherson observes that the “libertarians and southern conservatives of the 1980s and 1990s who wanted to revive the exclusively negative form of liberty that prevailed before the Civil War were right to make Lincoln a target of their intellectual artillery.”
Unlike these one-dimensional philosophers of negative liberty, however, Lincoln understood that secession and war had launched a revolution that changed America forever. Eternal vigilance against the tyrannical power of government remains the price of our negative liberties, to be sure. But it is equally true that the instruments of government power remain necessary to defend the equal justice under law of positive liberty. (p. 867)
This, of course, is also the view of American liberalism–the liberalism of F.D.R. and L.B.J. and the modern Democratic Party. When conservatives invoke freedom they usually intend to restrict it to negative liberty in McPherson’s sense (although even this commitment is often more honored in the breach than the observance). Freedom from taxes, from regulation, from restrictions on gun ownership, etc. are all framed as negative freedoms. Liberals maintain, though, that government power is necessary to ensure a degree of positive freedom sufficient for people to lead flourishing lives. This is the theoretical basis for the social welfare state and government regulations on nominally private activity, such as pollution. Lincoln may not have been a “liberal” in the modern sense, but there’s a relatively straight line from his political philosophy to New Deal-Great Society liberalism.
Disturbingly, though, the increase in positive liberty often seems to go hand-in-hand with a diminution in negative liberty. We only need to recall Lincoln’s suspension of habeas corpus, F.D.R.’s internment camps, or Obama’s “kill list.” That’s the legitimate insight of the libertarians (and their left-wing cousins the anarchists)–that it’s hard to establish a firewall that confines government power to good purposes. So you end up with an expanded welfare state and civil liberties violations and overseas wars. That doesn’t mean that a free, peaceful, and social democratic society is impossible (the Scandinavian countries seem to pull if off fairly successfully); but it may be a risk inherent in the project.