so i've wondered for a long time about how leftists use the terms 'materialism' and 'idealism', and how it relates to those terms usage in broader philosophical discussions on epistemology.
i may be incorrect in my interpretations, but it seems to me that leftist uses of the term (even its usage in some of marx's writings, from what little i've read) are such that 'materialist' means 'understands that the material conditions of a society drive its development via dialectical processes' and that 'idealist' means 'focuses on artificial/socially constructed ethical or legal principles (such as 'freedom' and 'democracy' and 'rule of law' and 'free speech') rather than material conditions of society like quality of life, literacy, etc.'.
the broader philosophical definitions of these terms are slightly different, however.
epistemologically, a 'materialist' is someone who believes that we can (and do) directly apprehend the mind-independent external world. this is contrary to epistemological idealism, which argues that we can only ever know the contents of our own mind. we can use these contents to infer things about 'true reality' but can never truly verify them.
ontologically, materialism argues that all of reality can be described in terms of physics, or that all facts of the universe are causally dependent on or reducible to physical processes. this is again opposed to Idealism, which argues that existence is in some way irreducibly and fundamentally mental.
so my first question for you beautiful posters is, are my perceptions of these definitions and usages overall correct or incorrect? How exactly does Marx (or Engels or any other marxist philosopher) use these terms, and do they intend an epistemological, ontological, or other interpretation? am i missing something fundamental about the philosophical definitions or about the colloquial/leftist usage? What's the deal with that 'philosophy is pointless, the goal is to change the world' quote, is understanding reality not a benefit for efficiently manipulating it?
My next point, is that it seems to me like Marx and Engel's Dialectical Materialism, or at least the political program and methods of Socialism/Communism, are not necessarily at all incompatible with either philosophical Idealism or Materialism, in terms of epistemology or ontology. Neither is necessarily incompatible with basic empiricism, but is rather a difference in interpretation of what our empirical knowledge is. Whether reality is fundamentally mental or matter, it consists of opposing energies and dialectical processes that play out in our experience with the extrinsic appearance of physical matter. Whether the world is in the mind or 'really out there', our experiences of it are the same.
A bit ago i stumbled across this article that seemed to be making a similar point, a point i've never really seen made by anyone else before. I haven't read past the abstract yet, and It seems like someone random person's college dissertation or thesis or something so I'm probably not well read enough to interpret this without context, so i was wondering if anyone had seen any similar discourse? What would Marx, Engels, Lenin, Stalin, or Mao say about this line of thought? is it a heresy against socialism, a useless detour into pointless philosophical questions that serve no practical purpose for the revolution, or is it something potentially useful in framing Marxism's relationship to epistemology and ontology?
I haven't looked through the paper linked yet, but I think that their definition of materialism develops through a negation of Hegel's system, since M&Es' "world systems" are heavily taken from the systems Hegel posed himself.
I think a close reading of how the structure of dialectics comes to being and develops through Hegel and subsequently through M&E will show that this dichotomy is more about one's orientation within the domain of natural and social sciences as knowledge machines for understanding reality rather than strictly about epistemology or ontology (it is in fact a bit of both).
As an aside, these latter categories and frameworks about what's real (i.e. the existence quantifier in logic) are framed by rigid analytic traditions that took off in Anglo philosophy where philosophers agonize in circles over what constitutes reality. Here, materialism is often denoted as "metaphysical realism", i.e. the mind independent stuff. Things-in-themselves as notions are brainteasees and an analytical struggle with this will not help any revolution whatsover. Social facts and social reality are real to us, whethe electrons are negatively charged in and of themselves is really intellectual brainmelt M&E rightly stayed away from. (For a cool way out of this hellscape, check out ontological structural realism.)
In more continental-leaning proses I find philosophers often prefer to de-emphasise such heavy categorizations; you can say the point of German idealism is to establish connections between what's in our mind and what's in front of us, rather than to separate the two.
Back to Hegel and M&E. It seems like materialism is the recognition that nature as constantly developing over time has always been changing, and will change forever. As such, there is no need for a beginning or end in an endless flow (and thus no creation, no Absolute Idea or God). To align our minds and knowledge to this nature means to recognize that science is a process of finding present understandings and synthesis, which can over time become too abstract and divorced from new development (it becomes a dogma), but then also recognizing the need to make concrete new ideas from new development, which is akin to progress in science. "Materialism" would be the constant strive to produce interpretations in accordance with nature's ebbs and flows instead of imposing what we think it should be. If "idealism" is in tension with this, then it fails to recognize the process I just described, like imposing principles and laws as universals or as static and unchanging. Very undialectical.
This brings me onto "ontology materialism", which, to answer your question, I think they, or at least Engels, never intended to understand "matter" as an essence/substratum. Anyway, I think dialectical science is against a universal appraisal of Cartesian reductionism which intends to unify all sciences under one lineage (physics -> chemistry -> biology and so on). I think it's still fine to say events are caused but what kind of substrata things belong to aren't really a part of M&E's materialism.
this concept of materialism is indistinguishable from empiricism though, and serious ontology, idealist or not, religious or not, has to account for the evidence we can verify with our senses somehow. I agree that no kind of ontology will really help a revolution more than any other as long as empirical methods are used, and that it doesn't really matter what 'reality' is 'made out of', i guess the different uses of the words confuse me.
the only real consequence of this discussion for me, and i may be revealing some strong, maybe even unsettling emotional and ethical biases here, involve:
CW: self harm
the question of the existence of the self, the value of human minds, and the question of suicide. in other words the meaning of life. under certain formulations of strict ontological physical reductionist materialism, the human mind, the self, literally does not exist (see Daniel Dennett for this kind of onotology), it is illusory, basically the same as a complex computer operating system - just mindless matter bumping into each other according to deterministic physical rules producing a fictitious theater that allegedly represents the 'real world'. in this kind of universe, there is no non-arbitrary reason to avoid suicide or death of any kind. i can strive for pleasure, but its also meaningless, the same as striving for death or love or revolution. the experiences of others are literally not real in this kind of ontology so they do not and can not matter, the feelings of hurt and the suffering i might cause to myself or others are fundamentally the same as the sun shooting out a jet of plasma or a rock falling down a cliffside. i might as well be smashing a casio calculator watch under my boot as a human skull. wars might as well be two really big sprockets grinding against each other or a volcano going off. there is not even the possibility of 'inventing meaning', anything in my 'mind' is an illusory appearance of physical matter and nothing more. the only conclusions i come to under this worldview are suicide or hedonism or a bastardized amoral and nihilistic kind of egoism.Under Idealism, however, or at least certain formulations of it, Mind is the only thing that i can really ever know does exist, and this opens up the possibility (but does not definitively prove) that others have minds as well - in physicalism, we do not assume that the world we can immediately perceive is all that exists, and i see no reason to interpret idealism differently in this regard - who knows how much mind there could be 'out there'. this doesn't necessarily make 'life' or the experiences of others meaningful, but in this worldview they definitely exist and are therefore worthy of some kind of consideration or contemplation. there is a real 'me' in this kind of world, a real mind that really experiences real suffering and real feelings, and since my real experiences show that others i see behave similarly to me but in noticeably different configurations every time, i can infer that others likely have real minds and real experiences that really mean something to them. that are not just rocks bumping into each other and producing fictitious self-referential representations of its surroundings.
if someone can convince me that this interpretation of the conflict between idealism and materialism is somehow logically flawed or incorrect or otherwise not the way one should look at the question, i would love that, i have been struggling with existential despair for years. solving the most fundamental questions in life is probably not within the purview of a community like this however.
Empiricism is a narrower concept. It requires one to setup a system which defines "evidence", "verification", and a criterion for "true knowledge", and probably more. Afaik, Marx did not busy himself with this, and both him and Engels did not like the static manner in which British empiricism treats knowledge and reality.
While this "materialism" might sound positivistic, it isn't just merely about empirical evidence (where do raw senses stop and interpretive perception starts?) but rather it's more about aligning and rationalising our cognition as to make sense of everything (myself and everything else); to encompass as much of the whole and not only selective parts of it that bode well to our feelings and will-to-power (like superstitions or irrationalism, or fascism).
At this point I've strayed far from existence and "true meaning", which you've discussed under the CW section. You mentioned physicalism and lost of "meaning", and idealism, or turning to the primacy of minds, as an existential escape from this. Here, you come round to justify meaning with inferences from seeing others. Not that there's anything inherently wrong with that, but some will take issue in analytical philosophy of minds and the like, with all kinds of problems: hard problem of consciousness, problem of other minds (solipsism) etc.
You've mentioned meaning quite a lot that I think you should additionally look at phenomenology for the existential question, maybe with Merleau-Ponty, then all kinds of feminist philosophy, metaphilosophy, hermeneutics, philosophy of history etc.
I have found this top down approach more empowering than looking for answers to life within the rigid framework of (often white men's) Anglo philosophy that, from bottom up, relies too heavily on the existential quantifier, a literal logical notation, to more fully deliver meaning to life.
to add (if i may) feminist epistemology and it's critiques of science and the dominant epistemic practices were quite eye-opening and informative for me.