Knowledge and affirmation of the ultimate needs and possibilities historically open to the revolutionary class and the means necessary to realize them.
Class consciousness and constitution as a political subject
From the moment the proletariat appears in its antagonistic position to bourgeois society as a whole, it is forced to assert generic human needs. As a class universally denied by capitalism, it can only form itself in a self-recognition process, a self-affirmation of its own program, communism, and of the means to make it a reality (internationalism, centralism, etc.). In other words, the process of constitution as a class is, above all, a process of gaining consciousness.
In the development of the productive forces, a phase is reached in which productive forces and means of communication and exchange emerge which, under the existing relations, can only be sources of harm, which are no longer such productive forces but rather destructive forces (machinery and money); and, at the same time, a class emerges which is condemned to bear all the disadvantages of society without enjoying its advantages, which is driven out of society and forced to place itself in the most determined contradiction to all other classes; a class which would be formed of all members of society and from which is born the consciousness that a radical revolution is necessary, communist consciousness.
Marx and Engels. The German Ideology, 1846
Class consciousness is not a "state of mind" nor is it born from it. It is born from a historical necessity that is inscribed in the very being of the proletariat as an exploited and revolutionary class: the only interests it can consistently defend are those that reflect generic, universal human needs. In any struggle, however small, it needs to affirm a practice that, even unconsciously, reveals itself to be internationalist and centralist, a way of confronting the order of things that dissolves all the barriers, all the particularisms, oppressions and privileges produced by an alienated society.
It is not a question of knowing what this or that proletarian, or even the proletariat as a whole, is momentarily proposing as an end. It is about knowing what the proletariat is and what it must historically do according to its being. Its aim and its historical action are mapped out for it, in a tangible and irrevocable way, in its own situation of existence, as in the whole organization of bourgeois society today.
Marx and Engels. The Holy Family, 1844
Class consciousness, emancipation and revolution
The development of this consciousness that expresses historical necessity is only achievable in the course of class struggle. When Marx insists that "the emancipation of the workers will be the work of the workers themselves" to the point of placing it as the motto of the First International, he is stressing that class consciousness does not "come from outside", but is born and develops within the class movement itself. Because the key word is "emancipation". Emancipation does not mean socialism, but liberation from tutelage, from the patronage of the ruling class's thinking. The emancipation of the workers is the process of their liberation from the dominant ideology, a process that blends in with revolution itself.
Both to bring about this communist consciousness en masse and to carry the thing itself forward requires a mass transformation of people that can only be achieved through a practical movement, through a revolution, and therefore revolution is not only necessary because the ruling class cannot be overthrown in any other way, but also because only through a revolution will the overthrowing class be able to come out of the muck it is sinking into and become capable of founding society on a new basis.
Marx and Engels. The German Ideology, 1845
Emancipation and militant expressions of the working class
That class consciousness is not something imposed or "inoculated" from outside the class does not mean that it develops in a homogeneous way. The proletariat is not only the last revolutionary class, it is also an exploited and oppressed class and as such cannot develop its widespread consciousness from the very first moment.
The proletariat, when it does not react, is only the force by which capitalism reproduces itself by taking advantage of the general apathy of its historical enemy. The working class is then only an amorphous conglomerate of people who manage to survive as best as they can in an unbearable society, reproducing the atmosphere of competition and enmity, the unhealthy spirit of capitalism. In a word, it does not act as a class with common interests in the face of capitalist vermin.
At other times, however, the proletariat acts together as a class carrying the only possible human future: communism. Then two kinds of societies can confront each other, one reactionary and the other revolutionary.
Between these two states of fact and these same facts there are individuals who are revolutionaries regardless of the momentary state in which the class as a whole finds itself, only their number varies according to the social situation. They are revolutionaries because they are aware that their goal and that of the class as a whole is communism.
These revolutionary individuals tend to organize themselves by affinity of ideas, ideas that do not fall from the sky but come from a particular interpretation of the history of the class struggle. Lessons are learned from every confrontation between capital and the proletariat, from which revolutionary theory is born and from which it evolves.
G. Munis. Revolutionary organization and activity, 1979
The role of these cupellations is fundamental. They are specific organs in which, collectively, groups of workers and related elements develop the critique (=demolition) of ideology from the historical experiences of the class in order to nourish and provide direction (=meaning) to present and future class struggles.
The objective conditions of the communist revolution are not sufficient to guarantee its victory, and the subjective conditions will not necessarily be generated by the former. The subjective conditions are nothing other than the theoretical consciousness of previous experience and of the ultimate possibilities offered to the proletariat; it is the longing knowledge of human action and the readiness to change its subjective existence into an objective existence.
G. Munis. Party-state, Stalinism, revolution. 1976
This subjective element forms the party in becoming, present and necessary from the first political manifestations of the proletariat. It is not an external body or an entelechy. It is the process of the constitution of a conscious minority with effective capacities of political leadership of the whole class. It unites, therefore, programme and will of action, although its constitution is not a voluntary act, but a parallel development to that of the constitution of the class as a party of the bourgeois society and finally, dominant class in socialism, transitioning to its own disappearance as class, communism. Party and class are therefore two dimensions of the same process of the constitution of the proletariat as a political subject.http://dictionary.marxismo.school/Class consciousness