[2162.] The present infinitive active gradually approached the character of a verb, and the original substantive nature being forgotten, it was supplemented by a passive, and by forms for completed and for future action, active and passive.
[2163.] The infinitive has furthermore two other properties of the verb: (a.) it is modified by an adverb, not by an adjective; and (b.) it is followed by the construction of its verb.
[Old and Poetical Use of the Infinitive.]
[2164.] The infinitive denotes purpose: (a.) when loosely added to a substantive in old Latin, (b.) with verbs of motion, eō, veniō, currō, mittō, in old or poetical Latin, and (c.) in the combination dō bibere, give to drink, in old, colloquial, or poetical Latin: as,
([a.]) occāsiō benefacta cumulāre, Pl. Cap. 423, a chance to pile up kindnesses. Parallel with a gerund: summa ēlūdendī occāsiōst mihi nunc senēs et Phaedriae cūram adimere argentāriam, T. Ph. 885, I’ve now a splendid chance the greybeards of eluding and Phaedria to rescue from his money cares. (b.) recurre petere rē recentī, Pl. Tri. 1015, run back to get it ere it is too late. voltisne eāmus vīsere? T. Ph. 102, do you think we’d better go to call? parasītum mīsī nudiusquārtus Cāriam petere argentum, Pl. Cur. 206, my parasite I sent four days ago to Caria, to fetch the cash. nec dulcēs occurrent ōscula nātī praeripere, Lucr. 3, 895, nor shall thy children dear come running kiss on kiss to snatch. nōn nōs ferrō Libycōs populāre penātīs vēnimus, V. 1, 527, we are not come with steel to harry Libya’s hearths. (c.) bibere dā usque plēnīs cantharīs, Pl. Per. 821, keep giving on to drink with brimming bowls. bibere is thus used by Plautus, Terence, Cato, and Livy, and by Cicero once with ministrō. In classical prose, purpose is expressed by the subjunctive with ut or a relative pronoun, or by a gerund or gerundive with ad or causā.
[2165.] In poetry, the infinitive of purpose is used with synonymes of dō also, and with verbs of leaving, taking away, taking up, &c.
huic lōrīcam dōnat habēre, V. 5, 259, on him a corselet he bestows to wear. trīstitiam et metūs trādam protervīs in mare Crēticum portāre ventīs, H. 1, 26, 1, sadness and fears I’ll to the wanton winds consign, to sweep into the Cretic sea. quis sibi rēs gestās Augustī scrībere sūmit? H. E. 1, 3, 7, who takes it on himself Augustus’ deeds to pen? quem virum aut hērōa lyrā vel ācrī tībiā sūmis celebrāre? H. 1, 12, 1, what hero or what demigod dost thou take up, to ring his praises on the rebec or the piercing pipe?