The spirit of resentment forms the dark heart of Marxism, its viral load, to pursue the analogy, and the dialectic its protective mechanism of transport. For Marxism to affect and infect its host, though, it must exploit its weaknesses. One vulnerability is clearly the existence of actual injustices in society, of which there is an endless supply. The other is the susceptibility of a proportion of the population with above average narcissistic tendencies. Though most people are narcissists to some degree, people with several traits associated with narcissistic personality disorder5 are highly susceptible to radical ideologies, not only leftist, but also far-right, Islamist, and animal rights and environmentalist extremism, for example.