a. [a. F. facultatif, -ive, f. L. facultātem: see FACULTY and -ATIVE.]
1. a. Of enactments, etc.: Conveying a ‘faculty’ or permission; permissive as opposed to compulsory; hence of actions, conditions, etc.: Optional.
1820. Ann. Reg., II. 718. In forming these quotas, neither the facultative departmental centimes, nor the communal centimes shall be taken into account.
1839. W. O. Manning, Law of Nations, V. vii. (1875), 387. Creating what is called ‘occasional,’ ‘accidental’ or ‘facultative’ contraband.
1861. M. Arnold, Pop. Educ. France, 50. What was … to use a French expression, facultative to the communes, what … they did or not as they liked.
1881. Times, 1 July, 9/6. The great schools … treat classics as obligatory, and science as merely facultative.
1884. Quarterly Review, CLVII. April, 403. Permit even for the Latin clergy a ‘facultative’ celibacy, leaving the door open, when necessary, to honourable marriage.
b. transf. Used by scientific and philosophical writers for: That may or may not take place, or have a specified character.
1874. Lewes, Probl. Life & Mind, I. 139. The Facultative Actions are those which … are … neither inevitably nor uniformly produced when the organs are stimulated, but … take sometimes one issue and sometimes another.
1875. H. Walton, Dis. Eye, 621. The facultative [hypermetropia] is present when objects can be accurately seen at any distance.
1884. Syd. Soc. Lex., Facultative hypermetropia … those cases of hypermetropia in which objects at an infinite distance can be distinctly seen both with and without convex glasses.
2. Of or proceeding from a faculty.
1866. J. Martineau, Ess., I. 154. Every facultative activity that goes out from me. Ibid. (1888), Study Relig., I. I. i. 55. A purely inward process, viz. the play of an a priori facultative activity with the matter of our sensitive passivity.
Hence Facultatively adv. rare, in a facultative manner or degree, contingently.
1877. Garnsey, trans. De Bary’s Fungi, 360. Certain facultatively parasitic … species of Moulds.
