Not only did Marx and Engels in The German Ideology give reproduction a "subordinate" fundamental status compared with production. They did it by the following sleight of hand: in part population increase or the success of reproduction somehow makes reproduction less important in "entering into historical development" as a "fundamental condition" (or "prmary historical relation" in another translation; also, "basic aspect of social activity"). This is quite a misogynist dialectic, given that "men" are in the first premise and the third premise, but women only are mentioned explicitly in the latter. It is also an idealist philosophical error, because the theory now tends to abstract from the real social life of individuals in reproduction.
Another passage in The German Ideology demonstrates the same sort of magical rather than scientific use of "dialectic" with respect to reproduction, and in this case the impact on the materialist philosophical consistency of their argument is more direct and explicit. They say:
Only now, after having considered four moments, four aspects of primary
historical relations,do we find that man also possesses "consciousness". But
even from the outset this is not "pure" consciousness. The "mind" is
from the outsed afflicted with the curse of being "burdened" with matter, which
here makes its appearance in the form of agitated layers of air, sounds,
in short, of language. Language is as old as consciousness...language
like consciousness, only arises from the need, the necessity, of
intercourse with other men...Consciousness is, therefore, from the very
beginning a social product, and remains so as long as men exist at all.
Consciousness is at first of course, merely consciousness concerning the
immediate sensuous environment and consciousness of the limited
connection with other persons and things outside the individual who is
growing self-conscious... This sheep-like or tribal consciousness receives
further development or extension through increased productivity, the
increase in needs, and , what is fundamental to both of these, the increase
in population. With these there develops the division of labor, which was
originally nothing but the division of labor in the sexual act, then the division of
labor which develops spontaneously or "naturally" by virtue of natural
predisposition (e.g. physical strength, needs, accidents etc., etc.) Division
of labor becomes truly such from the moment when a division of material and
mental labor appears. From this moment onwards consciousness can
really flatter itself that it is something other than ocnsciousness of existing
practice, that it really represents something without representing
something real (as the semioticians' signifier is abitrarily related to what it
signifies -C.B); from now on consciousness is in a position to emancipate
itself from the world and to proceed to formation of "pure" theory, theology,
philosophy, morality, etc.
In this long paragraph (only partially quoted), we see Marx and Engels's early formulation and explanation of the origin of what Engels later famously dubbed the fundamental question of philosophy -materialism or idealism ? - is rooted in the "second" original division of labor. For some reason, the "first" original division of labor, which gives women equivalent complementary status with men, just disappears and is replaced by a productive division of labor, between "men's" minds and hands. And to make it worse, once again, the "reason" the reproductive division of labor disappears as an ongoing fundamental determinate throughout history is its own success in creating a population explosion. This seems to be an error of substituting a negative and destructive dialectic in thought for what in being and becoming is the most fundamentally positive nad fruitful dialectic in human history - reproduction.
Here is a key connecting point: then Marx and Engels (whom I love dearly) substitute for the reproductive division of labor a productive division of labor as the fundamentally determining contradiction of historical development. This division of labor, between predominantly mental and predominantly physical labor, becomes the root of development of classes, the importance of which is declared in the first sentence of the Manifesto. Yet, Marx and Engels commit the same error of abstraction at one level that they criticize at the next level: the error of mental laborers in abstracting from the concrete reality of physcial labor. This is also seen from the fact that they keep depending on "population increase", which is another name for reproduction and "the sexual act", to explain the origin of increased "productivity" and "needs", which seem to be the "premises" for the division between material dn mental labor (and are because of the role of material surpluses in making possib
le creation of the class of predominantly mental laborers). Thus, we might say that the original idealist philosophical inconsistency of Marxist materialism is abstraction from reproduction.
For a fuller historical materialism , the theories of workers liberation and women's liberation must be integrated. This may be done on the basis of Marx and Engels's fundamental logic carried out more consistently. Feminism need not be added on to , but derived from the original premises.