At the risk of sounding trivial (coming on the heels of the discussions of tyranny and inevitable economic devastation), another reason Marxism must be opposed is that it is fundamentally incompatible with several other systems, all of which are worth preserving in their own right.
Incompatibility with USA version 1
Why is Marxism fundamentally incompatible with the US Constitution? I claim that it violates the 5th Amendment, specifically the final clause, “nor shall private property be taken for public use, without just compensation.” There would seem to be no question that even the mildest form of Socialism would involve government ownership of the means of production, distribution and exchange of a particular sector of the economy. Whatever sector of the economy would be nationalized in the future is certainly private property now, and thus nationalization would involve a “taking.” The federal government has, of course, nationalized the railroads (temporarily with Presidential and Congressional concurrence during World War I), temporarily nationalized specific companies before (like Smith & Wesson, also during World War I), and at least once the President has attempted to unilaterally nationalize an entire industry (in the case of the 1952 steel strike – it’s unclear whether this takeover would have been temporary or not since it had no statutory basis). The closest we get to a true, permanent industry nationalization is probably the formation of Amtrak in 1971. We can certainly argue whether or not the service is worth the ongoing government funding, but the nationalization of passenger rail service itself was pretty noncontroversial because the passenger-service assets that were nationalized were of negative value to the rail companies that held them – they all wanted out!
Thus, it’s unclear precisely how the Supreme Court would respond to a hostile, permanent, industry-wide taking of the sort necessary to institute even the mildest form of Marxism in the US. The issue would be the determination of “just compensation.” The government would likely argue that total market cap at the time of the seizure would be just, but there is no way to avoid the market distortions that rumor of the impending seizure would produce. Furthermore, I claim that compensation in such a case would be owed not only to the owners of the property taken, but to the industry’s entire current and future customer base, since the industry is converting to a monopoly and thus the future exchange gains for customers will be severely limited since those exchanges will no longer be free and competitive. I certainly realize that no court is likely to agree with me, since there is no way to determine the amount of such compensation, but it is still just; the fact that it’s not quantifiable is simply another reason why such nationalization cannot be allowed under the 5th Amendment.
At any rate, business valuation of an entire industry is itself an impossibility. Business valuation principally looks at present value of predicted future cash flows, which are estimated based on continuation of the current regulatory and competitive regime. To accurately value an entire industry, one must assume away all competitive advantage and competition-driven innovation. Valuing the telephone manufacture industry for takeover in, say, 1970 would have missed entirely the value in the whole smartphone industry (not to mention the value for consumers resulting from the smartphone industry). “Just compensation” in this case is simply impossible to ascertain, so it must be replaced by “best guess at market value.” This may be a reasonable approximation for a single company in a competitive industry, but not for the industry as a whole.
Incompatibility with Christianity*
This may seem to be an odd statement, given that one frequently sees claims that Jesus was a Socialist. These claims appear to be predicated on misunderstandings of both Jesus and Socialism. Fundamentally, they appear to miss the point that Christianity, while it certainly commands generous care for the poor, mandates that this be done voluntarily, not by the government, backed up by the threat of violence. This is explicated quite well by Larry Reed here (and more expansively here), so I need not expend too many pixels on the subject.
This argument, however, only shows that Marxism is not required by Christianity, not that it is incompatible with it. To see the incompatibility, let’s look at something even more fundamental in Christianity: the Ten Commandments prohibition on covetousness in Exodus 20.17 (as well as the restatement in Deuteronomy 5.21). I mention also that this is reiterated in Romans and James, so is clearly not part of the Mosaic Law superseded along with the dietary and ceremonial laws.
Covetousness is prohibited not only because it can lead to theft or adultery (since they are separately prohibited earlier in the same list), but also because it leads to ingratitude, social instability and an unhealthy focus on material things, social position and power. Marxism flips this script and says that covetousness is not a sin, it’s a sacrament. Not only is covetousness not wrong, it’s the fundamental basis for organizing society, the fundamental reason behind the revolution ushering in the Marxist utopia.
This is one of the reasons that Marxism inevitably fails: pre-revolution, it fosters covetousness in order to breed revolution in the belief that, post-revolution, the covetousness that drove the revolution will simply vanish. Humans being human, though, it doesn’t. The covetousness that initiated the revolution is still there driving social instability after the revolution, but there’s no coherent basis on which to deprecate covetousness, especially since it was so important in starting the revolution.
Another incompatibility between Marxism and Christianity arises from the Christian command to defend the poor. Marxism, of course, claims to improve the lives of the poor, but any improvements are always short-lived; the poor may get a higher proportion of the “pie” under Marxism, but the pie shrinks so rapidly that the actual standard of living of the poor drops fairly quickly under Marxism. Then, of course there’s the whole tyranny thing – the pain under tyranny always falls disproportionately on the poor, who lack material resources to buffer against it.
I should also mention here that the Frankfurt School (esp. Lukács and Adorno) certainly thought that Christianity was the major reason global Marxism had failed to achieve global domination – THEY thought the two were incompatible. In addition, the Neo-Marxist philosopher Gramsci (also discussed here) said, “Socialism is precisely the religion that must overwhelm Christianity”**
*this also applies to Judaism and, at least to some extent, Islam.
**Since the original of this quote has eluded some commentators, in Italian it is “che il socialismo è precisamente la religione che deve ammazzare il cristianesimo” and appears in the 4th paragraph of Audacia e Fede in Sotto la Mole available here.