THE INFINITIVE.
Infinitive without Subject Accusative.
[326]. This is used chiefly as Subject or Object but also as Predicate or Appositive.
NOTE.—The Infinitive was originally a Dative, and traces of this are still to be seen in the poetical use of the Infinitive to express purpose; as, nec dulcēs occurrent ōscula nātī praeripere, and no sweet children will run to snatch kisses.
A. As Subject.
[327]. 1. The Infinitive without Subject Accusative is used as the Subject of esse and various impersonal verbs, particularly opus est, necesse est, oportet, juvat, dēlectat, placet, libet, licet, praestat, decet, pudet, interest, etc.; as,—
dulce et decōrum est prō patriā morī, it is sweet and noble to die for one's country;
virōrum est fortium toleranter dolōrem patī, it is the part of brave men to endure pain with patience;
senātuī placuit lēgātōs mittere, the Senate decided (lit. it pleased the Senate) to send envoys.
2. Even though the Infinitive itself appears without Subject, it may take a Predicate Noun or Adjective in the Accusative; as,—
aliud est īrācundum esse, aliud īrātum, it is one thing to be irascible, another to be angry;
impūne quaelibet facere, id est rēgem esse, to do whatever you please with impunity, that is to be a king.
a. But when licet is followed by a Dative of the person, a Predicate Noun or Adjective with esse is attracted into the same case; as, licuit esse ōtiōsō Themistoclī, lit. it was permitted to Themistocles to be at leisure. So sometimes with other Impersonals.