performed on a more or less voluntary basis, or on a more or less involuntary basis, in which there are many gradations. Method of payment (remuneration or compensation) – The work done could be paid "in cash" (a money-wage) or "in kind" (through receiving goods and/or services), or in the form of "piece rates" where the wage is directly dependent on how much the worker produces. In some cases, the worker might be paid in the form of credit used to buy goods and services, or in the form of stock options or shares in an enterprise. Method of hiring – the worker might engage in a labour-contract on their own initiative, or they might hire out their labour as part of a group. But they may also hire out their labour via an intermediary (such as an employment agency) to a third party. In this case, they are paid by the intermediary, but work for a third party which pays the intermediary. In some cases, labour is subcontracted several times, with several intermediaries. Another possibility is that the worker is assigned or posted to a job by a political authority, or that an agency hires out a worker to an enterprise together with means of production. Criticisms Wage labour has long been compared to slavery. As a result, the term "wage slavery" is often utilised as a pejorative for wage labour. Similarly, advocates of slavery looked upon the "comparative evils of Slave Society and of Free Society, of slavery to human Masters and slavery to Capital," and proceeded to argue that wage slavery was actually worse than chattel slavery. Slavery apologists like George Fitzhugh contended that workers only accepted wage labour with the passage of time, as they became "familiarized and inattentive to the infected social atmosphere they continually inhale[d]". According to Noam Chomsky, analysis of the psychological implications of wage slavery goes back to the Enlightenment era. In his 1791 book On the Limits of State Action, classical liberal thinker Wilhelm von Humboldt explained how "whatever does not spring from a man's free choice, or is only the result of instruction and guidance, does not enter into his very nature; he does not perform it with truly human energies, but merely with mechanical exactness" and so when the labourer works under external control, "we may admire what he does, but we despise what he is." Both the Milgram