"rudiments or fundamentals of anything," by 1914, from basic. Also see -ics. Phrase back-to-basics was in use by 1962.
Entries linking to basics
basic adj.
"relating to a base," 1832, originally in chemistry, from base (n.) + -ic.
-ics
in the names of sciences or disciplines (acoustics, aerobics, economics, etc.), a 16c. revival of the classical custom of using the neuter plural of adjectives with Greek -ikos "pertaining to" (see -ic) to mean "matters relevant to" and also as the titles of treatises about them. Subject matters that acquired their English names before c. 1500, however, tend to be singular in form (arithmetic, logic, magic, music, rhetoric). The grammatical number of words in -ics (mathematics is/mathematics are) is a confused question.