In his contribution to the famous 1949 collection of essays by ex-Communists titled The God That Failed, Arthur Koestler carefully illustrates how set language binds thought to ideology at the expense of evidence. Koestler, author of the unparalleled novel of Stalin’s show trials, Darkness at Noon, describes a conversation he had early in his Communist career with “Edgar,” his Party contact, in which they discuss the front page of a Communist newspaper.

“But every word on the front page is contradicted by the facts,” I objected. Edgar gave me a tolerant smile. “You still have the mechanistic outlook, he said, and then proceeded to give me the dialectical interpretation of the facts . . .

Gradually, I learned to distrust my mechanistic preoccupation with facts and to regard the world around me in the light of dialectical interpretation. It was a satisfactory and indeed blissful state; once you had assimilated the technique, you were no longer disturbed by the facts [emphasis added].

Here, recounting his experience as a German Communist in the 1930s, Koestler is nonetheless describing the post-Communist, postmodern, post-9/11 American condition. It is the sinister overhaul of language and thought—so familiar!—that he personally engaged in, and that was and is the primary tool of Marxist and Islamic subversion. “Not only our thinking, but also our vocabulary was reconditioned,” he explains. “Certain words were taboo.” Certain other words became telltales by which to identify dissenters or enemies. Literary, artistic, and musical tastes, he writes, were “similarly reconditioned” to support the renunciation of independent thought and logic necessary to submit to ideology.

We cast off our intellectual baggage like passengers on a ship seized by panic, until it became reduced to the strictly necessary minimum of stock phrases, dialectical clichés and Marxist quotations… To be able to see several aspects of a problem and not only one, became a permanent cause of self-reproach. We craved to be single- and simple-minded.

We crave this, too, or just go along with it, which is worse. And the U.S. government itself is happy to oblige:

“Don’t Invoke Islam.”

“Don’t Harp on Muslim Identity.”

“Avoid the Term ‘Caliphate.’ “

“Use the terms `violent extremist’ or `terrorist.’ ”

“Never Use the Term ‘Jihadist’ or ‘Mujahideen.’ ”

These instructions are direct quotations from “Words that Work and Words that Don’t: A Guide for Counterterrorism Communication,” a guide put out by the National Counterterrorism Center on March 14, 2008 – and yes, that was under President George W. Bush. This crackdown on speech and, by extension, habits of thought, and, finally, thought itself extends across the political spectrum. Naturally, it has only gotten worse.

Such is the spawn of liberty’s rendezvous with totalitarianism.

Diana West is the author of American Betrayal: The Secret Assault on Our Nation’s Character (St. Martin’s Press), from which this essay is adapted.