Is "One Flew over the Cuckoo's Nest," satire or comedy, and why?
It is both.
The book written by Ken Kesey reflects the 60's counter-culture attitude to established post war society. It is both comedic and satirical but it is also ironic, full of pathos, is a critique of the system and it could be seen as inspirational. It is also an allegory, using the scenario of the mental institution to savage the system.
Kesey uses this setting to highlight how conformity to the norms and values of society is prized above all else and anyone who challenges this will be crushed by the system. McMurphy is the only sane patient, yet he is the only one who does not have the power to be released.
The symbolic use of names such as Nurse Ratchet emphasises the crushing nature of the system.
The film adds another dynamic. Milos Forman the director was Czech and he used the film as an allegory to illustrate the forced use of drugs on dissidents within Soviet bloc countries. The system is always right so if you challenge it you must be mentally unstable. Thus is the warped logic of not only totalitarianism but also of global capitalism.