The question posed in the subtitle seems to invite trite comparisons. And, at first glance, that's what Reynolds seems to provide:
Booth and Brown — and, surprisingly enough, Lincoln himself — were conjoined on a deep level by what in that era was called “the higher law.” They were inclined to follow the dictates of the higher law — moral or religious principle — rather than human law. Reconsidering Booth’s murder of Lincoln in light of John Brown and the higher law leads to troubling questions. When is violence in the name of a higher cause justified, and when is it not? Can we distinguish between bad terrorism and good terrorism?But he doesn't let the question rest with that pat non-answer.
Reynolds in a single column doesn't come up with what has also eluded the rest of humanity so far, a normative standard that provides clear guidance for the legitimacy of all uses of violence. Or even for the various forms of political violence.
We do have positive law standards that address the issue. One of the criteria of being a successful state as opposed to a "failed state" is whether the state has a "monopoly on violence." Which basically means that it's police and the court and penal systems that enforce the laws, who decide who is breaking the law and who isn't, who goes free and who doesn't. André Munro describes the concept in State monopoly on violence Encyclopædia Britannica Online 04/22/2015:
State monopoly on violence ... [is] the concept that the state alone has the right to use or authorize the use of physical force. It is widely regarded as a defining characteristic of the modern state. ...And he notes a qualification relevant to Reynold's topic, "The state monopoly on the legitimate use of physical force can be challenged by a number of nonstate actors such as political insurgents or terrorists or by state actors such as the military forces claiming autonomy from the state."
As the use of the term legitimate underlines, this concept does not imply that the state is the only actor actually using violence but rather that it is the only actor that can legitimately authorize its use. The state can grant another actor the right to use violence without losing its monopoly, as long as it remains the only source of the right to use violence and that it maintains the capacity to enforce this monopoly. The state monopoly on the legitimate use of violence is also not refuted by the use of illegitimate violence. Criminal organizations may undermine order without being able to challenge the state monopoly and establish themselves as a parallel source of legitimate rule.
International law also defines what kind of violence is legitimate, as well, in laws regarding the use of force in international relations and in civil conflicts, including the treatment of prisoners of war.
Part of why any comprehensive normative standard regulating political violence is so hard to come by is simply that real political violence takes places in concrete historical circumstances. The border between ethics and pragmatism is difficult if not impossible to define precisely.
Walter Benjamin wrote in his 1921 essay, "Critique of Violence" that neither natural law nor positive law were sufficient his analysis of political violence, declaring that the necessary perspective "can be furnished only by a philosophico-historical view of law."
Reynolds looks at the concept of "higher law," really a variation of natural law, that was shared at least in the abstract by John Brown, Abraham Lincoln and Lincoln's assassin John Wilkes Booth. Booth as a soldier was actually present at Brown's execution by the State of Virginia in 1959, exercising its own political violence via positive law: "For Booth, Lincoln and other antislavery politicians were duplicitous and treacherous. In 1860, as he witnessed the rise of Lincoln and his fellow antislavery Republicans, Booth wrote that John Brown was far nobler than Lincoln, since, in Booth’s words, 'open force is holier than hidden craft.'”
But in the end, the historical significance of the three men, of the history in which their acts of violence took place, has to be judged not just for their individual acts but for their cause and the results. Booth's cause was slavery. John Brown and Lincoln were partisans of democracy and enemies of slavery. Their antislavery cause was the more just from the standpoint of democracy, honest Christianity and common human decency than Booth's was.
And so, on the fateful evening of April 14, 1865, three forms of higher law mingled explosively: that of Brown, who inspired Booth, though from the opposite vantage point of racial equality; that of Booth, who believed God-backed terrorism could preserve white supremacy; and that of Lincoln, who cited “the judgments of the Lord” to promote a holy war against slavery. Of the three, Lincoln has of course been best received by history, and we can say that his form of higher law—channeled as it was through American institutions like the electoral process and presidential proclamations—is indeed the most admirable. The loose-cannon higher law actions of Brown and Booth seem out of bounds, for these men acted outside of institutions, without the sanction of some larger group. To be sure, both Brown and Booth, by turning to violence, succeeded in galvanizing change. Brown did become a martyr in the North and was a major inspiration to Union troops as they marched southward, singing their favorite song, “John Brown’s Body,” quickly adapted by Julia Ward Howe as “The Battle Hymn of the Republic.” That’s why many antislavery leaders attributed the fall of slavery largely to John Brown’s heroic example.And we winds up with what can legitimately be described as "a philosophico-historical view" of these three practitioners of the "higher law":
... Lincoln is not just a unifying national icon. He is a lasting example of the proper use of the higher law: that is, the principled pursuit of justice through a popularly elected government. Although lone-wolf higher-law types like John Brown and John Wilkes Booth sometimes have positive results, history has shown that the higher law of individuals can also be a slippery slope that leads to unleashed violence. At Gettysburg, Lincoln announced “a new birth of freedom” for “this nation, under God”—a higher law declaration. But in the next breath he expressed a firm commitment to preserving “government of the people, for the people, by the people.” Even the most apparently virtuous aims, Lincoln knew, can be dangerous if they are not channeled through a democratically chosen government.Reynolds here is more restrained in his judgment of John Brown that I am willing to be. Brown's participation in the Underground Railroad to free slaves was the right thing to do. The pro-democracy, anti-slavery guerrilla war in which he participated in "Bloody Kansas" was the right cause, the pro-democracy cause, and the proslavery cause was both despicable and antidemocratic. Brown's attempt to set up an armed antislavery band in the Appalachians, the plan thwarted by his capture at Harper's Ferry, was also a legitimate and pro-democracy cause, though it's hard to see how positive law could ever specifically sanction his actions.
But the proslavery advocates also were willing to throw positive law to the winds, as Brown saw live and person in Kansas territory. Ultimately they were willing to discard the positive law of the United States entirely and stage a most certainly violent rebellion against the Constitutional government.
Reynolds is the author of John Brown, Abolitionist: The Man Who Killed Slavery, Sparked the Civil War, and Seeded Civil Rights (2005), which I recommend highly.