On May 5th, 1818, Karl Marx, hero of the international proletatiat, was born. His revolution of Socialist theory reverberates throughout the world carries on to this day, in increasing magnitude. Every passing day, he is vindicated. His analysis of Capitalism, development of the theory of Scientific Socialism, and advancements on dialectics to become Dialectical Materialism, have all played a key role in the past century, and have remained ever-more relevant throughout.
He didn't always rock his famous beard, when he was younger he was clean shaven!
Some significant works:
Economic & Philosophic Manuscripts of 1844
The Eighteenth Brumaire of Louis Bonaparte
Critique of the Gotha Programme
Manifesto of the Communist Party (along with Engels)
And, of course, Capital Vol I-III
Interested in Marxism-Leninism, but don't know where to start? Check out my "Read Theory, Darn it!" introductory reading list!
Free market trade has existed and changed shape throughout most of human history. Advice with how to deal with it is in the Old Testament. how often or consistent it revolved around a common currency is/was constantly changing, though
For most of human history (tribal / pre-agricultural societies), markets were rare and mostly unecessary. Small groups of people survived by foraging / hunting for food and sharing it among themselves. Usually elders, or some type of communal decision-making process was how food was distributed. Sharing, not trade, was the distribution system.
You can have some trade in tribal / feudal societies, but it isn't the most common way that goods are distributed.
The idea of a "free market" is an invention of capitalism in the last few hundred years. Laissez-faire was coined by French businessmen in the late 1600s.
I'm just saying that, one of the oldest known written texts, waaay before than when the old testament was written, is a customer complaint where they mention copper coins as currency. We don't know how common copper coins were, but saying that capital based societies are "young" is not correct either.
https://en.m.wikipedia.org/wiki/Complaint_tablet_to_Ea-n%C4%81%E1%B9%A3ir
Capital and money are not exactly the same thing. Capital is money used to make more money through (1) ownership of the means of production, (2) wage labor, and (3) economic rent & fincancialization.
The existence of coins does not imply a capital-based society, in the same way the emergence of personal computers in the 70s does not mean the economy of the 70s was highly computerized.
Check out David Graeber's Debt: The First 5000 Years for some anthropology on how exchange worked in early societies. Trading currency for goods or services was the exception, not the rule.
Currency isn't Capitalism, though. Capitalism has currency, but not all systems with currency are Capitalist.