The social significance of an idea is not necessarily proportional to its truth, its coherence, or even its comprehensibility. In his introduction to a new edition of Warrant for Genocide, which is the history of the concoction of The Protocols of the Elders of Zion, a clumsy forgery that even now has a certain political resonance for the susceptible and weak-minded in an important region of the globe, Norman Cohn writes:

It is a great mistake to suppose that the only writers who matter are those whom the educated in their saner moments can take seriously. There exists a subterranean world where pathological fantasies disguised as ideas are churned out by crooks and half-educated fanatics for the benefit of the ignorant and superstitious.

Nor, of course, is all writing concerned with communicating ideas, at least in any sense that an intellectual might recognize.

I first learned...