What is Dialectical Materialism?
To understand this philosophical current must understand materialism and dialectics (both contributions comes "dialectical" concept). Materialism holds that the brain is preeminent on the thought, that in more simple words we translate as that thinking owes its existence to the brain. This is a response to the idealism, whose represent is supported on the premise of René Descartes "cogito ergo sum" ("I think therefore I exist") and Emmanuel Kant which leads to the most far this thinking. As well, they believed that the existing phenomenon could not be understood if there isn't a thinking being, so thought is first to the observed phenomenon since it would be irrelevant for something to happen if it is not possible to understand it through thoughts prior to the phenomenon. Of course, this raises many questions that materialists solved in a very blunt way: no brain, no thoughts therefore (phenomenon) is first that thought.
In terms of the dialectic, we will say that the word originates from the Greek "dialektikos" which we translate as "talk"technique and already in latin is mentioned as an "art". The dialectic is interpreted in different ways according to the area of study and over time the concept has also changed. For philosophy, is where most interested, not only represents the dialogue between people, translates into a process by which the thought is expressed in words. For Kant and his followers is an illusory process but is Hegel who gives the dimension that we know today: the dialectic is a process that is based on an experience, into something concrete, that generates a series of thoughts that explain it and that together we call thesis. At the same time generated other thoughts that raise doubts about the thesis and which in turn produce another explanation which is called antithesis.
Between both schools of thought are engages in a kind of dialogue which has resulted in a new more complete explanation which we call synthesis. Over time the synthesis becomes a new thesis and the process is repeated. To finish with the dialectic say that Hegel applies it in most of the case where there is power, for example the relationship employer and similar relationships. Here is where Marx and Engels take the bases of historical or dialectical materialism. According to them that moves the historic change is the change in the sources of production (Marx) is an economic phenomenon (Engels).
Production would divide the world between those who produce and those who consume it, leaving amid those who acquire wealth with the Exchange. Then according to these approaches are social classes will engage in this kind of dialogue of power, each with the power to produce (the working class) and the class that can acquire and enrich itself with the production (the bourgeoisie). The relationship between both classes would be born political systems that we know and the various social divisions, since there are actually more social classes as the economic phenomenon is more complex. For them feudalism (example used to clarify their ideas and coming to be the thesis) ceases to comply with the regulatory role that had in the middle ages and gives place to the monarchical absolutism (the antithesis) as a way of making the noble class retain power but instead gives rise to the power of the bourgeoisie (in particular with the French Revolution and represents the synthesis) that does not attempt to Another thing that benefit from it (although the ideal was another: the equality of all before the law).
So let's look at a more recent example we can take as a thesis to the dictatorship of the Somoza's in Nicaragua, the antithesis comes to be the sadinista revolution and their synthesis the Government that was formed after overthrowing the dictator. Later this Government had its own antithesis in the famous "counter-revolutionaries" or "cons" and as a result we have a new synthesis in the Government of Violeta Chamorro. We can identify similar processes in many of our countries today day, clear that on one scale much smaller than the Marx and Engels used and perhaps most up-to-date, because whether we like it or not, still a very high percentage of the world's population lives under the shadow of this thought. I need only say that day historical or dialectical materialism that we know today is due to the contributions of Lenin, who adapted it to the situation of Russia and Mao which in turn makes its adaptation to China or mention the contributions of many theoreticians over a hundred years.