By Karl Marx and Frederick Engels
As we were discussing Leontiev's work on activity theory in my spring seminar, one of my graduate students said that his focus on labor sounded a lot like The German Ideology. I hadn't read the book, so I picked it up. Am I glad I did? Sort of.
As the editor's introduction states, this version is abridged. Much of The German Ideology consists of "detailed line by line polemics against the writings of some of their contemporaries" (p.1), which sounds about as edifying as reading through YouTube comments. Or Lenin. The editors courteously curated the text, leaving what I would consider to be the more interesting stuff.
In this book, Marx and Engels lay out the materialist method to history. They argue that men [sic] began to distinguish themselves from animals when they began to produce their means of subsistence (i.e., labor) (p.42). We are what/how we produce; the mode of production is "a definite form of activity, a definite mode of life" (p.42). And the relations of nations depend on their productive labor and its division (p.43). Marx and Engels review the stages in the development of division of labor (p.43; discussed in Capital and in The Origin of the Family, Private Property and the State).
Critically for my interest in cultural-historical theory: The production of life is seen as "a double relationship": both natural and social (p.50; cf. Vygotsky). And "language is practical consciousness that exists also for other men, and for that reason alone it really exists for me personally as well; language, like consciousness, only arises from the need, the necessity, of practical intercourse with other men. ... Consciousness is, therefore, from the very beginning a social product, and remains so as long as men exist at all" (p.51). Later in the book, they argue that "language is the immediate actuality of thought" (p.118).
The authors go on to claim that as long as there is a division of labor, there is a sphere of activity from which man cannot escape. But in a communist society, he can do what he wants—he can take on whatever occupation he likes whenever he likes (p.53). The authors do not go into how a person would develop expertise in these different areas, but they do declare later that "private property can be abolished only on condition of an all-round development of individuals" (p.117; cf. Vygotsky's "The Socialist Alteration of Man").
"Empirically," the authors claim, this ideal communist society "is only possible as the act of the dominant peoples 'all at once' and simultaneously, which presupposes the universal development of productive forces and the world intercourse bound up in communism" (p.56; recall that this worldwide revolution was considered to be a must in the early days of the Soviet Union, and Stalin only got around to revising this doctrine in 1938, after it became clear that a worldwide revolution was unlikely).
The authors drive home the argument that history is material, progressing due to material results; circumstances make man (p.59). In a communist society, "the original and free development of individuals ... is determined precisely by the connection of individuals" (p.118).
In all, reading through this book helped me to see deep connections with Vygotsky's thought about language, but also Leontiev's focus on labor making man. It wouldn't be my first recommendation if you're new to reading Marx and Engels, but it's worth reading in a supplementary sense.