1387, "branch of speculation which deals with the first causes of things," from M.L. metaphysica, neut. pl. of Medieval Gk. (ta) metaphysika, from Gk. ta meta ta physika "the (works) after the Physics," title of the 13 treatises which traditionally were arranged after those on physics and natural sciences in Aristotle's writings. The name was given c.70 B.C.E. by Andronicus of Rhodes, and was a ref. to the customary ordering of the books, but it was misinterpreted by L. writers as meaning "the science of what is beyond the physical." Hence, metaphysical came to be used in the sense of "abstract, speculative" (e.g. by Johnson, who applied it to certain 17c. poets, notably Donne and Cowley, who used "witty conceits" and abstruse imagery). The word originally was used in Eng. in the singular; plural form predominated after 17c., but singular made a comeback late 19c. in certain usages under Ger. influence.