Memes are meanings, i.e. iso-functional neuroanatomical constructs corresponding to signs in the sense of Ferdinand de Saussure.
An essential characteristic of memes is that linguistic meanings have the nature of nonconstructible sets in the mathematical sense and do not abide by constraints governing Aristotelian logic, such as the principle of the excluded middle.
Language is a mutualist symbiont and enters into a mutually beneficial relationship with its hominid host.
Yet individual grammatical and lexical meanings and configurations of memes mediated by language may be either beneficial or deleterious to the biological host.
The symbiosis is rendered more complex than just simple mutualism, both by the physiological discrepancy between language as an overall condition and the nature of individual ideas conveyed through language, as well as by the ecological difference between vertically and horizontally transmitted memes.