If you want to claim Marxists have a singular codex, The Wealth of Nations fulfils this role for capitalist economists, even if capitalists rarely understand what it's actually saying. Marx was very much influenced by Smith. No, nonono, NO. The Manifesto is functionally a political pamphlet, even if a long one, and its purpose was propaganda* as easy reading. The Manifesto is something you usually read in high school. It's usually thrown about among non-Marxists as some kind of Bible, which it isn't, and this is especially a problem when it comes to understanding what Marxists actually think. It's clear from the OP that you weren't much enfranchised in Marxism, and that's fine, but I'd suggest you don't listen to people discussing Marxism by taking that text that seriously as a primary nexus of discussion. It outlines the general historical idea of Marxists, yes, but it doesn't go much into detail about how Marxists think this comes to pass. If there's any codex, it's Das Kapital. Which is also a good book - even if you don't agree with Marxism, it describes some very real structural problems in capitalist economies, many of which Marx foresaw and came to pass. Of course, there are other economic works that better outline the issues more succinctly, with no overt communist intention, and written later. But beware, these works are usually done by spooky leftists. Sidenote, and please people, let's not make this thread a Marxism vs. Capitalism thread, but the whole idea of the Manifesto as some elevated Bible goes vastly beyond popular spaces, and is sometimes entrenched in hack right wing academia. The Peterson-Zizek discussion was the biggest facepalm in my life for this reason. EDIT: *By propaganda, I mean it in its strictest sense, ie not the common usage that it's ill-intended manipulation. It's a political text with an agenda. English is not my first language.