- positive (adj.) - early 14c., originally a legal term meaning
"formally laid down," from Old French positif (13c.) and
directly from Latin positivus "settled by agreement, positive"
(opposed to naturalis "natural"), from positus, past participle
of ponere "put, place" (see position (n.)). Sense of "absolute"
is from mid-15c. Meaning in philosophy of "dealing only with
facts" is from 1590s. Sense broadened to "expressed without
qualification" (1590s), then "confident in opinion" (1660s);
mathematical use is from 1704; in electricity, 1755.
Psychological sense of "concentrating on what is constructive
and good" is recorded from 1916. - positive (n.) - 1520s, from
positive (adj.).