Why is the ninth month called September?
c.1200, mycrocossmos (modern form from early 15c.), "human nature, man viewed as the epitome of creation," literally "miniature world," from Middle French microcosme and in earliest use directly from Medieval Latin microcosmus, from Greek mikros "small" (see mica) + kosmos "world" (see cosmos). General sense of "a community constituting a world unto itself" is attested from 1560s. Related: Microcosmic. A native expression in the same sense was petty world (c.1600).
A representation of something on a much smaller scale. Microcosm means “small world,” and in the thought of the Renaissance, it was applied specifically to human beings, who were considered to be small-scale models of the universe, with all its variety and contradiction. (Compare macrocosm.)
(from Greek mikros kosmos, "little world"), a Western philosophical term designating man as being a "little world" in which the macrocosm, or universe, is reflected. The ancient Greek idea of a world soul (e.g., in Plato) animating the universe had as a corollary the idea of the human body as a miniature universe animated by its own soul. The notion of the microcosm dates, in Western philosophy, from Socratic times (Democritus specifically referred to it)-i.e., from the 5th century BC. Propagated especially by the Neoplatonists, the idea passed to the Gnostics, to the Christian scholastics, to the Jewish Kabbalists, and to such Renaissance philosophers as Paracelsus. The supposed analogy between the whole and its parts served not only to develop a cosmology in which the reality of the individual received due attention but was also fundamental to astrology and other fields in which belief in a metaphysical relationship between man and the rest of nature is postulated. In later philosophy the monadology of G.W. Leibniz presented a comparable view of man and the universe; and, in the 19th century, Rudolf Lotze chose Mikrokosmus as the title of his major work on the theory of knowledge and reality.