JOHN BROWN, RATIONAL HERO
New York City
I’m an admirer of both David Reynolds and Martin Duberman, but I’m sorry that Duberman, like Barbara Ehrenreich in the New York Times and Adam Gopnik in The New Yorker, seems to see Reynolds as the first reputable historian to argue that John Brown was not insane but a rational and effective hero [“The Avenging Angel,” May 23]. All these enthusiastic critics ignore Albert Fried’s 1978 John Brown’s Journey: Notes and Reflections on His America and Mine. Fried challenged the work of Allan Nevins and C. Vann Woodward, who argued that Brown was mad, a monomaniac.
Viewing Brown through the perspective of the civil rights struggle of the 1960s, Fried saw the deep moral rationality and effectiveness of Brown’s life and actions. His book was viciously assaulted in the Times by David Donald, a Southern historian who had previously suggested that Charles Sumner, the abolitionist senator, was demented. Fried was critical of the historical establishment, which invariably identified with the moderates in opposition to the “extremists.” Fried’s work deserves more attention.
PICKS BONE WITH EINSTEIN GROUPIES
I was pleased to see Joshua Foer’s excellent review of the reissue of the Born-Einstein letters [“The Other 1905 Revolution,” May 16]. However, I have a bone to pick with popular characterizations of the two most famous features of the theory: One is that E = mc2 is a logical consequence of the special theory of relativity (a claim repeated by Foer), and the other, that nothing can travel faster than light was a starting assumption of the theory (Foer does not make this claim). Both the equation and the limiting speed are, indeed, consistent with and integral to the elaboration of the theory, though they are not simply consequences of the standard postulates. Neither in the fifth paper in 1905 nor in his subsequent several attempts did Einstein derive the equation from the basic postulates purely logically. Additional (quite profound) assumptions were needed, and the fact that he made them only adds to Einstein’s revolutionary boldness of those years.
Determining whether one thing is a “logical consequence” of another can be a tricky game of semantics. Einstein himself wrote in a letter to Conrad Habicht in the summer of 1905, “A consequence of the study on electrodynamics [the special theory of relativity] did cross my mind. Namely, the relativity principle, in association with Maxwell’s fundamental equations, requires that the mass be the direct measure of the energy contained in a body; light carries mass with it.” It’s true that Einstein had to do more than just rearrange a few variables to get from his monumental June paper on relativity to September’s three-page derivation of E = mc2, but it’s also true that had Einstein not made this leap, someone else would have made it before long.