Marijuana belongs to a group of agents commonly known as hallucinogenics. "Psychedellics" also part of this grouping. While it is better to term marijuana into a class of "psychoactive compounds", I believe that this is getting too specific for your question.
As with other psychedelics, the effects of marijuana depend in part on how one interprets, uses, and learns to develop them. As pointed out by many researchers in the area of philosophical/psychological effects, the environment ("setting") is of great importance.
