 Sigmund Freud held that religion is nothing more than an illusion, or even a mental illness, and Marx claimed that religion is "the sigh of the oppressed," and the opium of the people providing only "the illusory happiness of the people," thus providing two influential examples of reductionistic views against the idea of religion.Linguistic reductionism is the idea that everything can be described or explained by a language with a limited number of concepts, and combinations of those concepts.An example is the language Toki Pona.