Suppose I read Gayatri Spivak and come across her concept of sanctioned ignorance. What method do I use to determine if this is a 'good' concept or not? I think that internal consistency is a good place to start but I don't know other criteria to use.
Spivak is a post-colonialist, which should immediately raise red flags, and not in a good way, because when did colonialism end exactly? Liberals have constructed entire worlds of abstruse terminology to cover up their support of the status quo. Whatever is useful in their work you will probably also find in far more valuable Marxist texts. “Sanctioned ignorance” is a fancy term for what we would call “being a fuckin’ lib.”
To put the question another way, what method did you use to come to the conclusion that Marxist texts are more valuable?
I used to work in academia, and I did some copy editing for a colleague who ran a journal, and sometimes we would get papers that were just impossible to understand. The abstracts were written in English while the bodies of the papers were usually written in Korean. She told me once that if the abstracts made no sense in English, the bodies of the papers weren't going to make sense in Korean, either. With the notable exception of Marx himself, who can sometimes be frustratingly obscure, I find that Marxist texts typically make a serious effort to communicate as plainly as possible, largely because their audience consists of people who may not even be able to read. I think Mao's On Contradiction, for example, is one of the greatest philosophical works ever written, and it's also stunningly easy to read compared to most other major philosophical texts (Plato is at a similar level of readability) specifically because it was written to aid illiterate peasants. While liberal texts are not completely worthless and while some of them are actually pleasant and interesting to read, I find that if a text appears to be purposefully difficult to understand, it may be concealing a lack of content.
I've also just found over the years that it's exceptionally difficult to make sense of anything going on in human societies without Marxist analysis. When it comes to history, your choices are basically Marxism or great man theory. Liberals attempt to find a middle path via historians like Weber, who will claim that capitalism comes from Protestantism or that an abstract and suspiciously god-like ideal like "culture" is just as important as the way people get their daily bread, but I find these attempts to be basically useless. I'm writing historical fiction at the moment, and it's just not possible to make sense of how people saw the world—what people did and why, how things worked and happened—without historical materialism.
I regularly see liberals attempting to form general laws of history based on the very limited evidence ("power corrupts," "getting rich makes you stupid," "capitalism is nothing but exchange"), and these formulations of theirs are just so vague that you can't really use them to make sense of anything, especially the rise of China. According to everything liberals know, China should have collapsed and bent the knee to the USA long ago, but it just keeps growing stronger as the USA correspondingly grows weaker. Only Marxism can explain this. Postcolonial theory is also useless when it comes to explaining other major geopolitical events—the Ukraine War, 9/11, the Iraq Invasion, you name it, because colonialism never actually ended. There is no "post"!