ANTI-DÜHRING: THE GENERAL INTRODUCTION 
Modern Socialism, says Engel's, is the product of the class war between capitalists and workers and the irrational anarchy rampant in capitalist production. Its theoretical elaboration is descended from the French philosophers in years just prior to the Great French Revolution. In a note we are informed that the FIRST socialists were Morelly and Mably.
Morelly published THE CODE OF NATURE in 1755. Nobody really knows anything about "Morelly" and this name might have been a pseudonym for either Francois-Vincent Toussaint OR Denis Diderot. Gabriel Bonnot de Mably (1709-1785) published ENTRETIENS DE PHOCION in 1757.
Engels says the French thinkers just before the Revolution were "extreme revolutionists" and means that as a compliment. They did not accept any authority except REASON. "Reason became the sole measure of everything." Engels then quotes HEGEL on the Revolution as a "dawn of a new day" the advent of the Kingdom of Reason. "All thinking beings," Hegel wrote in The Philosophy of History, "participated in celebrating this holy day."
Today we know that this "holy day" was not of Reason but was "the idealized kingdom of the bourgeoisie." Great as the French thinkers were (especially Rousseau with his Contrat Social) they could not "go beyond the limits imposed upon them by their epoch." And we should keep this in mind too when we read Engels (and Marx)-- these giants of the nineteenth century-- in the twenty-first century.
Capitalist development was still in its infancy in the eighteenth century and the bourgeoisie put itself forward as the representative of all the classes being oppressed by feudalism. The bourgeoisie, the workers, and peasants comprised "the people" against the exploiters (the feudal nobility). But there are always hints of the coming struggle between the bourgeoisie and its class allies. Engels gives three examples:
1. The Reformation-- The Peasant's War-- Thomas Münzer, the Anabaptists.
2. The great English Revolution-- The Levelers.
3. the great French Revolution [Engels likes to put "great" in front of any revolution]- Babeuf.
Engels says even though the workers as a class were just beginning to form in the sixteenth and seventeenth centuries there were still thinkers that had begun to express the interests of the future class, although in a utopian manner [Thomas More "Utopia" 1516, Thommaso Campanella "City of the Sun 1623]. Then came 'the three great utopians"-- i.e., Saint-Simon, Fourier, and Owen. What the three had in common, according to Engels, is that they presented systems of universal social salvation and did not base themselves on the working class as such.
All these systems, Engels says, end up in "the dust hole" just because they are as irrational as the bourgeoisie that they represent: in the last analysis they just can't work to liberate humanity. "To make a science of socialism," Engels says, "it first had to be placed upon a real basis."
So, part of the real basis was rooted in the French philosophers -- materialism and revolution, but something else was still needed-- dialectics. And that was provided by HEGEL. Hegel's philosophy was the high point of German philosophy. "Its greatest merit was taking up again of dialectics as the highest form of reasoning.
Hegel made advances on the philosophy of Aristotle ("the Hegel of the ancient world") and developed ideas first enunciated by the ancient Greeks. Other philosophers responsible for laying the real basis for socialism as a science who Engel's mentions are Heraclitus, Descartes, Spinoza, Diderot and Rousseau.
The Greeks saw a world in flux and change, everything in motion and change (for the most part at least, there were major exceptions) and they laid the foundations of modern science, also the Arabs (Muslims) of the middle ages contributed, but real modern science actually dates from the middle of the fifteenth century. Due to the influence of thinkers such as Bacon and Locke, Engels says, the idea of flux and dialectical thinking was given up and people began looking at the world as made up of unchanging forces and objects subject to immutable mathematical laws. Engels calls this "the metaphysical mode of thought" characterizing the eighteenth century. It will have to give way to the dialectical mode of thought before socialism can be scientific.
This won't be so difficult because, as Engels says, "Nature is the proof of dialectics" and the biggest blow against the metaphysical outlook was struck by DARWIN whose theory of evolution reveals a biological world in constant change and flux. But this theory can also be extended to the solar system and the universe itself as revealed by KANT and LAPLACE and their formulation of the nebular hypothesis which put an end to NEWTON'S eternally enduring universe. HEGEL, of course, saw the course of human history as an evolutionary development. So, by the mid nineteenth century the natural, biological, and human sciences were all poised to be studied with the dialectical method.
Hegel's idealism proved inadequate to a correct understanding of the world. Hegel's view was that the flux and change of evolution was the reflection in the material wold of the development and manifestation of the Absolute Idea, which when once achieved would then arrive at rest. Engels considered this an unresolvable contradiction-- that world of flux would end up at rest. So idealism is replaced by MATERIALISM which sees the process of change as unending. But Engels may have a contradiction too. Why should the social question end with the arrival of socialism. If flux is eternal why would not a socialist world also change and break up (as we have apparently seen happen around 1989-91)?
Perhaps we are getting ahead of ourselves. Lets stay with Engels' intro. We have arrived at scientific socialism based on science and a materialist outlook. We can make sense of the social question without resorting to metaphysics or utopian schemes. A scientific study of how capitalism works, that is the world economic system currently in place, is now possible. The secrete of capitalism is not revealed simply by enumerating its bad social consequences. That won't tell us how it works. The secrete is to reveal how SURPLUS VALUE works, how unpaid labor "is the basis of the capitalist mode of production."
There is a short second part of the introduction, "What Herr Dühring Promises" this is about six pages. I am only going to say a few words about this section. It is basically a series of quotes from Dühring's works showing what a ridiculous megalomanic he was. He claimed to have arrived at the absolute final truth about philosophy, science, socialism, etc., and anyone who disagreed with him was simply backwards and wrong. Engels mocks Dühring's oversized ego in this section.
Well, this is enough on the Introduction to Anti-Dühring. I will now proceed to Part One "Philosophy" and go over the fourteen chapters devoted to this topic. Keep in mind, that Engels doesn't see any role for modern philosophy over and above the role of science for understanding the world-- except for logic and dialectical thinking.