You and others keep wanting to somehow deflect from Fitzhugh and Calhoun the reality of their socialist, pro-slavery (same thing) positions on the grounds that either someone else (Marx) held them later, or someone else (Filmer) may have held them earlier. When evaluating them in historical context, this is appropriate. When evaluating their ideas as "philosophers" or theorists, it is totally inappropriate and misleading.
For example, one can evaluate Hitler's race hatred in historical context of the 1920s Weimar Republic---a reasonable thing to do---but it does not in any way change or exculpate his actual disgusting theories, which he continued to stand by. So when Fitzhugh says (to which none of you have a denial) that slavery is the ultimate form of socialism, or when Calhoun says that we must not only have guarantees that protect the ownership of slaves in principle but which PROHIBIT all criticism of slavery as an institution, then we have to take those as political/economic principles and evaluate them on their face.
What you are doing is “asserting the premise”.
Your premise is that Calhoun and Fitzhugh were socialists or marxists. But rather than making a case for this premise you simply write as if this were established fact. You assemble a series of facts where Calhoun and Fitzhugh appear to be in concord with Marxist belief and run with it.
In order to do so you ignore other sources of political thought that were known to influence these men (Filmer in Fitzhugh’s particular case), and you likewise ignore how their own positions contradict the positions of socialism. You ignore the fact that Marxism sees capitalism as a phase leading to socialism, while Fitzhugh was a critic of industrial capitalism entirely. The socialists weren’t trying to hold on to the pre-capitalist world of the ante-bellum South. Fitzhugh was.
Where do you find Marx or any other socialist of the 19th century defending slavery? You don’t. Not only that, but Marx was demonstrably a fan of Abraham Lincoln and the Union side in the Civil War. He was the author of that fan mail letter the First International sent to Lincoln.
Now I suppose it’s possible to cherry-pick Lincoln in order to show that Lincoln was a “Communist” at heart. Lincoln shut down newspapers in the North to control political thought, and jailed a few thousand political opponents without trial.
Like Marx he was a promoter of centralized, consolidated government. Marx advocated the income tax and Lincoln implemented one. Lincoln’s war against southern secession prefigured the Brezhnev Doctrine, once in you’re in you can’t get out. He waged a terrible war on his own country, something highly typical of the communist world.
So it’s not so hard to play this game. Look for the apparent similarities, ignore the inconvenient differences. The trouble is Lincoln never joined a socialist movement. Neither did Calhoun or Fitzhugh.