It was Bertrand Russell, the British philosopher and logician, who, although he himself became a confirmed socialist, pointed out that Bolshevism under Vladimir Lenin had become, in effect, a religion. (See ”The Practice and Theory of Bolshevism”.) The religious fervor of their adherents can blind them to the deeply flawed nature of their underlying philosophical presuppositions and operating principles. Russell could see that Bolshevism, in practice, was a very bad deal. Countless others of his generation, however, could not see the obvious. Russell's critique was one of how Bolshevism operated. It was not fundamentally a critique of Marxist theory. On the contrary, he defends Communism, per se, as being historically necessary to lift the bulk of mankind out of poverty. Nowhere in his essay, however, does he present a detailed defense of that position. His aim is to critique what Bolshevism had become.
Dietrich von HIldebrand, by contrast, presents a more detailed critique of Bolshevism in his essay "False Fronts" (reprinted in My Battle Against Hitler). His critique is grounded in a deeper understanding of human nature than the merely materialist conceptions of Nazism and Bolshevism. Indeed, he points out that Nazism and Bolshevism have much more in common they either has with Christianity. Here is what he writes in his concluding paragraph:
The ideological distinction between Bolshevism and National Socialism is not so very great, despite all the violent political animosity between them, which has totally different roots. One person might want to make an ally of Bolshevism while another may want an alliance with National Socialism, but the Catholic is separated from both by an unbridgeable abyss. He cannot choose between them, because they are essentially united on those critical points that separate them decisively from Christianity. All he can do is oppose both, pointing to Christ and the foundations of Christian Western culture, which alone constitute their true antithesis. He must see these ideologies as two equally dangerous, irreconcilable enemies of Christ.
A deep analysis of the foundations of progressivism, together with its historical connections with nazism, communism, population control and the eugenics movement will, in my humble opinion, ultimately lead a clear thinking person to the same conclusion regarding its incompatibility with true Christianity. Indeed, all of these movements lead to the all-powerful nanny state and the radical diminution of human freedom and moral responsibility. Describing Nazism as the extreme right-wing and Bolshevism (or Communism) as the extreme left-wing is simply to expose historical naivety and ignorance. Until a person reaches that conclusion, however, he or she is likely to flirt with either Bolshevism or Nazism as the be-all and end-all of historical progress, with progressivism being a stepping stone on that road. In reality Bolshevism and Nazism are simply two sides of the same anti-Christian coin, and progressivism represents a gamble with that coin.