The fundamental law of revolution, which has been confirmed by all revolutions and especially by all three Russian revolutions in the twentieth century, is as follows: for a revolution to take place it is not enough for the exploited and oppressed masses to realise the impossibility of living in the old way, and demand changes; for a revolution to take place it is essential that the exploiters should not be able to live and rule in the old way. It is only when the “lower classes” do not want to live in the old way and the “upper classes” cannot carry on in the old way that the revolution can triumph. This truth can be expressed in other words: revolution is impossible without a nation-wide crisis (affecting both the exploited and the exploiters). It follows that, for a revolution to take place, it is essential, first, that a majority of the workers (or at least a majority of the class-conscious, thinking, and politically active workers) should fully realise that revolution is necessary, and that they should be prepared to die for it; second, that the ruling classes should be going through a governmental crisis, which draws even the most backward masses into politics (symptomatic of any genuine revolution is a rapid, tenfold and even hundredfold increase in the size of the working and oppressed masses—hitherto apathetic—who are capable of waging the political struggle), weakens the government, and makes it possible for the revolutionaries to rapidly overthrow it.
(V.I. Lenin, “Left-Wing” Communism: an Infantile Disorder, 1920.)
The consciousness that the working class has to go through develops in stages – social awareness, social consciousness, and class consciousness. The first two stages develop more or less objectively or spontaneously. The latter stage develops subjectively or consciously, from the introduction of new ideas by the thinkers and conscious revolutionaries.
Generally, the level of consciousness today is social awareness — the becoming aware of what society is as it really is. The next stage is social consciousness, where the workers understand that they are members of a class and that they need class solidarity. They understand their class is exploited and that they must fight that exploitation. This stage is generally expressed in the formation of some kind of political party of the workers.
It is important to note that the American mass has never achieved even the stage of social consciousness. There was a moment following the Civil War when people came close to it. A certain level of unity existed around the abolition of slavery and for integrating the Freedmen into society. With the murder of Abraham Lincoln and the assumption of power by Andrew Johnson, a counterrevolution was launched and the moment was lost.
Class consciousness is where the workers grasp the necessity of taking political power in order to expropriate the expropriators and bring the class struggle to an end.
These stages should not be viewed categorically. The development of consciousness is a process, which reflects the stages of development and interaction of the economy and the social response of the masses. Ideas are constantly in formation, and the stages of development of consciousness interpenetrate one another.
http://www.lrna.org/2-pt/articles/v22ed1art3.html