Those of us who mostly know about Alexander Herzen from the works of Isaiah Berlin—which is probably just about everyone in the English-speaking world who has heard of him at all—probably have a clear image in their mind of who he was, and what he stood for. Among the various Russian socialists and revolutionaries of the nineteenth century, we know, Herzen stood out as the proto-liberal; the anti-totalitarian. When others dreamed of sacrificing whole generations and civilizations on the altar of Revolution, Herzen stood apart and begged for reason, temperance, and empirical methods.
It's the image of Herzen that found its way, for instance, into Tom Stoppard's The Coast of Utopia—itself based on Berlin's works. Those of us who have read Berlin's Russian Thinkers will recognize this version of Herzen easily: it's the reason he became one of our liberal heroes and archetypes before we'd even read him.