spontāneus

1. Sponte (πόθος) means voluntarily; whereas ultro, in an over-ready manner; so that sponte refers to the mind of the agent, ultro to the thing itself. Liv. x. 19. Orare ne collegæ auxilium, quod acciendum ultro fuerit, sua sponte oblatum sperneretur; and Tac. Hist. iv. 79. Suet. Cæs. 6. Sponte accusare means to accuse of one’s own accord; whereas ultro accusare means to obtrude one’s self into the office of an accuser, when one should be satisfied with not being one’s self accused; according to which, ultro accusavit may be resolved into the complete phrase: Haud contentus non accusari ab altero, ultro etiam progressus est, ut ipse accusaret alterum, or, ultro progressus accusavit alterum. 2. Sponte, from choice, is in opp. to casu, or necessitate, Colum. ii. 1, 13. Plin. Ep. v. 14. Tac. Ann. vi. 23; whereas sua sponte, quite of one’s own accord, like αὐτομάτως, in opp. to rogatus, provocatus, or invitatus. Cæs. B. G. i. 44. Cic. Fam. i. 7. iv. 3. vii. 5. (iii. 103.) 3. Sponte and spontaneus, like ἑκών and ἑκούσιος, paint the voluntary action as an act of the understanding; voluntate and voluntarius, like ἐθελοντής, as an act of the will, in opp. to invite; libenter and libens, like ἄσμενος, as an act of feeling, in opp. to tædio. (iv. 277.)