-ics

CIDE DICTIONARY

-ics,  

 A suffix used in forming the names of certain sciences, systems, etc., as acoustics, mathematics, dynamics, statistics, politics, athletics.  [1913 Webster]
"Mathematics have for their object the consideration of whatever is capable of being numbered or measured."
"Ethics is the sciences of the laws which govern our actions as moral agents."  [1913 Webster]
"All parts of knowledge have their origin in metaphysics, and finally, perhaps, revolve into it."  [1913 Webster]
"Mechanics, like pure mathematics, may be geometrical, or may be analytical; that is, it may treat space either by a direct consideration of its properties, or by a symbolical representation."  [1913 Webster]

OXFORD DICTIONARY

-ics, suffix (treated as sing. or pl.) forming nouns denoting arts or sciences or branches of study or action (athletics; politics) (cf. -IC 3).

Etymology

from or after F pl. -iques or L pl. -ica or Gk pl. -ika