Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class V. Words Releasing to the Voluntary Powers
Division (I) Individual Volition
Section I. Volition in General
2. Causes of Volition

615a. Absence of Motive.

   NOUN:ABSENCE OF MOTIVE; caprice [See Caprice]; chance (absence of design) [See Chance].
   VERB:SCRUPLE (be unwilling) [See Unwillingness]; have no motive.
   ADJECTIVE:AIMLESS (chance) [See Chance]; without rime or reason.
   ADVERB:CAPRICIOUSLY, out of mere caprice.