The first sections of Anti-Dühring were released in the German socialist press in 1877. The point of the prefaces is to establish a context, both for the original work and the new editions. In part, this includes what was happening in German philosophy at the time. It was, in a sense, a “fad” within scientific and philosophical circles, to create all-embracing “systems” that explained everything. It’s certainly understandable; the middle-late 19th Century spanned the period from the threshold of breakthroughs in nearly all of the physical sciences, to the time when such breakthroughs became commonplace. Before this period, it was still unknown how the transformation of the form of motion (for example, the emission of steam to the raising of a given weight a given distance) changed the calculation necessary to determine the quantity of motion; by the end of it, these laws were an accepted part of physics and casually used to make other calculations. In the middle of this period of discovery, it would be an almost irresistible temptation to come with a Grand Theory of Everything, and many people did–particularly those who had no knowledge of anything. Let us recall that Herr Dühring’s expertise–such as it was–was in the law. While this ought not to qualify him to speak of biology, physics, economics, &c, he was by no means alone in believing otherwise. In this, of course, nothing has changed.
This was also, more significantly, still early in the formation of German, and international, socialism. The Reichsbank, and all it said about German Imperialism, was only a year old. The Communist Manifesto, with its promise of a scientific basis for socialism, was not yet 30 years old; the first volume of Capital, which delivered on that promise, only ten. Russia and Turkey were gearing up for war. The ideas of Socialism were spreading throughout Europe fast enough that in only a year Germany would declare them illegal–which would, naturally, spur their growth even more.
If you have a rapidly growing movement based on difficult and complex political principles, it is very nearly foreordained that a great deal of confusion over those principles will occur. The tradition of free, open, lively, and far-ranging discussion within the socialist movement–brutally interrupted by Stalinsim, reestablished by Trotskyism–dates back to this period.
In the prefaces, Engels establishes some principles that will be important in understanding the book: “to me there could be no question of building the laws of dialectics into nature, but of discovering them in it and evolving them from it.” In general, laws of motion are deduced from facts–this applies to laws governing “nature” as well as laws governing “society.” I put quotes around those words to emphasize that, while many consider them opposites, there is, in fact, no reason to view society as anything but part of nature; hence no reason why the search for the laws of motion should be approached any differently.
Engels then goes on speak of advancements in science between 1877 and the time of the current preface (1885). “The old rigid antagonisms, the sharp, impassable dividing lines are more and more disappearing. Since even the last ‘true’ gases have been liquefied, and since it has been proved that a body can be brought into a condition in which the liquid and the gaseous forms are indistinguishable, the aggregate states have lost the last relics of their former absolute character….” and “Whereas only ten years ago the great basic law of motion, then recently discovered, was as yet conceived merely as a law of the conservation of energy, as the mere expression of the indestructibility and uncreatability of motion, that is, merely in its quantitative aspect, this narrow negative conception is being more and more supplanted by the positive idea of the transformation of energy, in which for the first time the qualitative content of the process comes into its own, and the last vestige of an extramundane creator is obliterated.”
He was wrong about that last, of course–the ever-creative theists, once it was shown that God was not, in fact, responsible for those things “science will never answer” retreated and took a new stand on matters “science will never answer,” such as the creation of life, which held good until the twentieth century, and when that fell, it turned into vague, abstract, and meaningless questions “science will never answer.” But in principle he was right, and for those with an interest in the history of religious thought, it is worth considering.
“And since biology has been pursued in the light of the theory of evolution, one rigid boundary line of classification after another has been swept away in the domain of organic nature. The almost unclassifiable intermediate links are growing daily more numerous, closer investigation throws organisms out of one class into another, and distinguishing characteristics which almost became articles of faith are losing their absolute validity.”
I do want to take a moment with this, because I think it is useful as a pointer to the method of dialectical materialism, which Engels will be demonstrating throughout the book: The materialist dialectic does not deny that categories exist in nature. But it does not treat those categories as rigid, inflexible, set for all time. There is, in other words, a real difference between a liquid and a solid–between water and ice. That difference isn’t just in our heads, it reflects actual differences in nature. But water and ice can transform into one another; there can be boundary conditions that blur the lines; there is motion and transformation of categories, as well as of the things that may be contained within them. So far, the only rigid, inflexible, permanent categorization known to exist is between science fiction and fantasy.
“The recognition that these antagonisms and distinctions, though to be found in nature, are only of relative validity, and that on the other hand their imagined rigidity and absolute validity have been introduced into nature only by our reflective minds — this recognition is the kernel of the dialectical conception of nature.”
Which is also true of society, and also true of the ideas with which we understand society. That it, this recognition not only drives Engels’ exploration in the book, but ought to drive our own investigation of the book. The critical approach, looking for truth that has become untruth, or categories that have changed, or discoveries that have negated what was then known, is the difference between the method of Marxism and dogmatism.