While German theorist Karl Marx rarely used the term "class consciousness", he did make the distinction between "class in itself", which is defined as a category of people having a common relation to the means of production; and a "class for itself", which is defined as a stratum organized in active pursuit of its own interests.
The psychic value of a human consists in being able to conceive (think) of the ends of their actions as purposeful ideas, which are distinct from the actions required to realize a given idea. That is, humans are able to objectify their intentions by means of an idea of themselves as "the subject" and an idea of the thing that they produce, "the object".
The theoretical basis of alienation within the capitalist mode of production is that the worker invariably loses the ability to determine life and destiny when deprived of the right to think (conceive) of themselves as the director of their own actions;