I originally wanted to kick off one of the chapters in Race Against the Machine with a quote from Karl Marx, but my co-author Erik Brynjolfsson talked me out of it. And I’m glad he did. Because the more I think about it, the more displeased with myself I am for suggesting it. In fact, I’m instituting a blanket rule for myself: from now on, no more quoting Marx, or citing or discussing his work.

I know that this sounds shortsighted or even dumb, especially now. The Great Recession and jobless recovery have caused many to see flaws in the basic system of capitalism. Marx helped define this system even as he ardently critiqued it. So why not re-examine his work now, as my fellow HBR blogger Umair Haque and many others have done?

I can think of two good reasons why not. The first, and less important, is that most of his ideas were profoundly lousy. As The Economist nicely summarized in 2002:

But the fact remains that on everything that mattered most to Marx himself, he was wrong. The real power he claimed for his system was predictive, and his main predictions are hopeless failures… Class war is the sine qua non of Marx. But the class war, if it ever existed, is over. In western democracies today, who chooses who rules, and for how long? Who tells governments how companies will be regulated? Who in the end owns the companies? Workers for hire — the proletariat. And this is because of, not despite, the things Marx most deplored: private property, liberal political rights and the market. Where it mattered most, Marx could not have been more wrong.

The second, much deeper reason for not giving Marx the courtesy of any intellectual acknowledgment is that his ideas and calls to action were responsible, pretty directly, for the deaths of tens of millions of people.

Does that sound like an overstatement? Here’s the call to action that closes his 1848 Manifesto of the Communist Party:

The Communists disdain to conceal their views and aims. They openly declare that their ends can be attained only by the forcible overthrow of all existing social conditions. Let the ruling classes tremble at a Communistic revolution.

Scholars and apologists have debated how much Marx really advocated violence, but followers like Mao, Lenin, Stalin, and Pol Pot seem to have taken ‘forcible overthrow’ pretty literally, and to have caused a great deal of trembling. The Black Book of Communism is the most thorough attempt to date to tally up the harm done around the world by Marxist revolutions and the states they yielded. Its authors arrive at a 20th century death toll of 94 million people, and a similarly horrific catalogue of cultural, economic, and environmental devastation This is the real-world fruit of Marx’s ideas. Do I even need to say that I want no part of it?

During the OJ Simpson trial the talk show host Dick Cavett said “if I converse with him at a cocktail party, I will say, ‘Well, there are so many people here who haven’t murdered anyone, I think I’ll go talk to them.'”

Well, there are so many thinkers about economics and technology who haven’t inspired mass murder and inhuman states. I think I’ll go engage with them.