> Finally, Marx's idea of "true reality" as the "obligation" and
> "final goal" of "any form of theoretical and practical
> consciousness" appropriates Hegel's idea that "it is spirit in its
> freedom, the summit of self-conscious reason, which gives itself
> actuality, and produces itself as the existing world."
Actually Marx's claims are that "true reality" is the "obligation" and "final goal" of "existing reality" and that by starting out from "any form of theoretical and practical consciousness" (e.g "political economy") it's possible for the "critic" to develop "from the forms peculiar to existing reality the true reality" as the "obligation" and "final goal" of "existing reality".
"True reality" is "freedom, the summit of self-conscious reason, which gives itself actuality, and produces itself as the existing world." In Marx, this is "communism", "the true realm of freedom". Another way of expressing this is that "freedom" in this sense is also the actualization of "human beings" as potentially "self-conscious reason", i.e. as "universally developed individuals". as "enlightened" individuals. "Freedom" is "the reality of the true human being".
So where, as in the various forms of "despotism", there isn't "freedom" in this sense, there also isn't "human being". Individual "consciousness" in such contexts is not fully "enlightened"; it's characterized by some degree of "superstition" and "prejudice", the degree depending on the degree to which existing relations are inconsistent with those required for the full development of "self- conscious reason".
"The monarchical principle in general is the despised, the despicable, the dehumanised man; and Montesquieu was quite wrong to allege that it is honour [Montesquieu, De l'esprit des lois]. He gets out of the difficulty by distinguishing between monarchy, despotism and tyranny. But those are names for one and the same concept, and at most they denote differences in customs though the principle remains the same. Where the monarchical principle has a majority behind it, human beings constitute the minority; where the monarchical principle arouses no doubts, there human beings do not exist at all." http://www.marxists.org/archive/marx/works/1843/letters/43_05.htm
"There is one characteristic of the 'agricultural commune' in Russia which afflicts it with weakness, hostile in every sense. That is its isolation, the lack of connexion between the life of one commune and that of the others, this localised microcosm which is not encountered everywhere as an immanent characteristic of this type but which, wherever it is found, has caused a more or less centralised despotism to arise on top of the communes." <http://www.marxists.org/archive/marx/works/1881/03/zasulich1.htm>
"Now, sickening as it must be to human feeling to witness those myriads of industrious patriarchal and inoffensive social organizations disorganized and dissolved into their units, thrown into a sea of woes, and their individual members losing at the same time their ancient form of civilization, and their hereditary means of subsistence, we must not forget that these idyllic village- communities, inoffensive though they may appear, had always been the solid foundation of Oriental despotism, that they restrained the human mind within the smallest possible compass, making it the unresisting tool of superstition, enslaving it beneath traditional rules, depriving it of all grandeur and historical energies. We must not forget the barbarian egotism which, concentrating on some miserable patch of land, had quietly witnessed the ruin of empires, the perpetration of unspeakable cruelties, the massacre of the population of large towns, with no other consideration bestowed upon them than on natural events, itself the helpless prey of any aggressor who deigned to notice it at all. We must not forget that this undignified, stagnatory, and vegetative life, that this passive sort of existence evoked on the other part, in contradistinction, wild, aimless, unbounded forces of destruction and rendered murder itself a religious rite in Hindostan. We must not forget that these little communities were contaminated by distinctions of caste and by slavery, that they subjugated man to external circumstances instead of elevating man the sovereign of circumstances, that they transformed a self-developing social state into never changing natural destiny, and thus brought about a brutalizing worship of nature, exhibiting its degradation in the fact that man, the sovereign of nature, fell down on his knees in adoration of Kanuman, the monkey, and Sabbala, the cow." http://www.marxists.org/archive/marx/works/1853/06/25.htm
Where "existing reality" is not "true reality" "human being" is "estranged" from its "species being" understood in this way.
To characterize it as "estrangement", however, is to characterize it as positively developmental of "reason". So it's possible to develop from its "forms", the "forms of existing reality" as forms of "estrangement", "true reality" - the actualization of "self-conscious reason" - as its "obligation" and "final goal".
Thus "the growing domination of capital" is "the estrangement which is growing and therefore hastening to its annulment. This is indeed the only way in which that which exists affirms its opposite." <http://www.marxists.org/archive/marx/works/1844/manuscripts/needs.htm>
These ideas explain the role assigned to "class".
"The propertied class and the class of the proletariat present the same human self-estrangement." http://www.marxists.org/archive/marx/works/1845/holy-family/ch04.htm
Ted