Karl Marx based his early critiques of capitalism upon one key concept: the alienation of labor under the capitalist economic system. This term is not based upon subjective (unique to each worker) feelings of estrangement or of difficult, tedious unsatisfying work (though anyone who has worked in a factory or cubicle may well attest to these as well). Rather, Marx based his idea of alienation upon the dehumanization of the worker. Under capitalism, working people become commodities, just like wheat or oil or copper. Workers under capitalism lose their status as free, thinking, creative beings, and become one among many other factors of production, commodities which may be purchased with wages by capitalists. This dehumanization, this objectification of free subjects, establishes the need of the worker to re-become a self-created, free individual. It is this need of the worker, Marx believed, which made the working class the class which, through the realization of this need, would lead the overthrow of the capitalist system.

The idea of alienated labor also shows one of the main ways in which Marx saw the class struggle expressed in modern society. There is constant conflict between the interests of the capitalists and the workers, and in this struggle, the worker is at a considerable disadvantage. He or she must always find a new job to continue living, but the capitalist may easily dispense of one worker and hire another. This illustrates perfectly the status of the worker as a commodity.

To delve further into this idea of alienated labor, we should examine the five aspects of alienated labor which Marx laid out in his Economic and Philosophical Manuscripts of 1844.

1. The worker is alienated from the product which his labor produces. When a worker produces an object, he does not own it, rather, it immediately passes into the capitalist's hands. Further, the wage which the capitalist pays the worker for the production of the object is obviously not the full value of the product, since the capitalist makes a profit.

2. The worker is alienated from the activity of labor itself. His labor reflects his boss's intelligence, will and creativity, rather than his own. The work is external to the worker. He is not required to use his own intelligence or creativity, he must only obey.

3. The worker is alienated from fulfilling work. The work which he performs has no possibility of being useful to the development of his talents or interest. This is because of the specialization and division of labor. The development of technology has caused the productive process to rely more and more on assembly lines where smaller and more menial parts of the overall process are performed over and over by one individual. So, even if a man is interested in learning how to make shoes, if he works in a shoe factory, he will merely be standing on an assembly line, punching holes in cloth or gluing rubber together.

4. The worker is alienated from his fellow man. The capitalist free market and the worker's status as a commodity forces each worker to adopt a selfish outlook and compete with other workers for jobs and wages. Each man is reduced to merely a means or a hinderance to each individual's success, in the eyes of each individual worker.

5. The worker is alienated from nature. The production process is very artificial, and nature ceases to mean what it should to men. Instead, it is divided up as property of capitalists and is only valued for its ability to produce resources to be used in the production process. Further, the worker is alienated from his human nature. Not only is he objecitfied as a commodity, but working, a process which could further and develop ones nature, becomes externalized. When a man hates his unfulfilling, uncreative, mindless job, the only times he feels truly human and free are when he is at home, when he is at a bar, or when he is with friends or women. The animal aspects of a man's nature become what make him happy, and the human aspect, producing something intelligently, creatively, and rationally, is replaced with mindless repetition which is hated.