The above writeup makes Marxism out to be very idealistic, when quite the opposite is true. This is likely becouse it's based on the "Communist Manifesto", rather than Marx's more intellectual work, "Das Kapital". I will, therefore explain Karl Marx and his world view according to the concepts presented it Capital.

First of all, Marx believed that the world was full of objects, and the observer was a subject. We must interact with the world of objects to "Reproduce our material goods", or live. As we interact with the world of objects, we change them. As subjects, our sum of experiences define us, define our personality, etc. So, as we interact with objects and change them, we change our experiences, and therefore change ourselves. This is the basics of dialectical materialsm. "What's this got to do with communism?" you ask? Hold on, it'll make sense in a bit.

Marx also looked back at history. Not the made-up history that the liberals Locke, Russeau, and Hobbes employed (solitary primitive being), but recorded history starting with the feudal era. He devided the sociatal infrastructure into 2 portions, the mode of production, and the relations of production. In the feudal era, the mode of production were the craft system, and the relations of production was aristocracy. The reason why the bourgeois revolution happened was because a new mode of production was coming around that allowed possibilites that the aristocracy wouldn't allow (namely, the accumulation of great wealth and power). In our current system, the mode of production is capitalism, and the relations of production is liberal democracy.

Now, on to the actual communism part. Marx didn't preach communism to save the women and children, he did it because he saw many contradictions of capitalism. As capitalists move more and more of their productive power over to machines to increase profit, they collectively create a smaller demand (economic demand, not real demand. If you've got 1,000,000 people who want your product, but only 10 are rich enough to afford it, you'r demand is 10.) for commodities by firing workers to save costs, which creates the boom-slump cycle of capitalism.

The proletariat, during a bad slump (such as the Great Depression, though it was avoided by bombing Germany), are supposed to realize that they are the ones who run the means of production, and the capitalists get rich off their labor without doing any actual work. Then they seize the means of production, and fire the owner of the company. A pretty anti-climatic revolution, no?.

After this revolution, they are supposed to realize that they collectively shape the world, which shapes the individuals in society. They realize that they shape history, and it becomes "True History"