The propensity to condemn others, usually writers, for what we might call guilt by inadvertent association is a method of abuse or disparagement often used by those who are incapable of intelligent rebuttal.  It is a technique favored by the left and its legion of trolls, who like to point out that an author quoted in a conservative argument has dubious affiliations or, analogously, that the founder of a political organization is responsible for some of the suspicious characters who gravitate around his banner.

In my own case, for example, I have been excoriated for citing passages from Friedrich Nietzsche and Martin Heidegger, who are certainly contestable philosophers, Heidegger in particular.  Yet Hannah Arendt, a much beloved political writer among the left and Jewish to boot, was Heidegger's student and lover and never disavowed him despite his Nazi sympathies.  I detest Heidegger and have no truck with his indigestible philosophical tomes, but many of his occasional essays are valuable contributions to modern thought.  They should not be readily junked.

More recently, I have been gleefully informed that authors whose insights I have referred to, such as Kerry Bolton and Vilifredo Pareto, among others, were conscripted by fascists.  This may be true, but it does not negate the substance of their arguments.  Tommy Robinson is another case in point.  He is routinely condemned for the outlying circle of mental asteroids – hooligans, Nazi sympathizers – attracted for reasons of their own to his laudable mission protesting the violence and social disruption perpetrated by the U.K.'s growing Muslim community.

In all such instances, opponents argue from fortuitous or external contamination rather than engage with the core thesis of an intellectual discourse or the fundamental purpose of a public enterprise.  This practice illustrates the refusal, typical of the left, to honestly address the political or intellectual position of those whom the left regards as beyond the pale.  If you can't shut them down, or rely on the heckler's veto, or fall back on mere ad hominem vulgarity – three other tactics with which we have grown all too familiar – Progressivists will proceed to condemn by accidental or heterodox association.  This approach purports to be intellectually effective, though it is wholly disingenuous – a form of psychological mobbing.

Like most authors on the conservative spectrum, I generally consult the writings of stalwart leftists as reconnaissance of the political terrain, and sometimes their views are worth considering or honorably contending with.  One cannot casually denounce George Orwell for having written Homage to Catalonia or Sydney Hook for Out of Step.  Among contemporaries, for example, Nick Cohen (even before his partial change of heart in What's Left?: How the Left Lost Its Way) or Christopher Hitchens or Terry Eagleton or Bernard-Henri Lévy were and are brilliant writers.  Even if one disagrees with some or most of their hypotheses, they cannot be cavalierly dismissed or slandered as contemptible proponents of a malign ideology.  They are not run-of-the-mill leftist thugs or professional liars, like so many of their party brethren.  I have read them carefully and with respect.  I once enjoyed an amiable dinner conversation with Eagleton, without feeling the need to resort to vituperation or condescension.

I had no doubt that they are, or were, basically wrong in many of the perspectives they defended, but their arguments needed to be met by counter-arguments and their writing styles acknowledged for lucidity and elegance.  One should not impugn their integrity.  This kind of decent response to adversaries' literature is often true of conservatives, but almost never to be found among the left.

Ironically, what these more thoughtful writers and thinkers of a socialist bent have failed to see is how they themselves, despite their partial repudiations or revisionary clarifications, have been recruited by the brutish and unscrupulous left – those who represent what Lévy in Left in Dark Times called the "new barbarism."  We might say they have unwittingly aided the unreconstructed left in its campaign to impose a socialist horror upon an imperfect but functional free-market society and economy that, for all its errors, has raised the living standards of untold millions – precisely that which socialism has systematically depressed.  They do not see how they have lent legitimacy to a depraved ideology.

One should not blame these exemplary figures for having their names inducted by the very barbarians they have tried to educate, any more than one can fairly sanction a conservative writer for citing the work of important authors who may have occasionally erred in their judgments or who have been drafted by the fascist fringe for its own nefarious agenda.  But one may fault the more benign socialists for their cognitive astigmatism.  This does not mean that one should employ the tactics of the left in censoring their work or vilifying their character.  Argument should be met by counter-argument where it is warranted.

The majoritarian left will not engage in reasonable discussion or intellectual debate or even intelligible, if heated, polemics.  It will, on the contrary, deploy totalitarian means of suppression to promote its cause: aspersion, defamation, obloquy, litigation, and outright violence, and it should be met with aggressive measures such as institutional disenfranchisement.  War is war.  Discerning socialist thinkers, however, should think twice before defending the indefensible – or, even better, recognize that revisionary pleading for a sinister movement is a dead letter.

As for their conservative counterparts, these should not hesitate to extract and develop the best ideas from the library of influential thinkers whom the left, usually deceptively, considers problematic, guilt by inadvertent association be damned.  For the vulpine left, good faith does not exist.  The guilt is all on their side.