§289. Adjectives used Substantively

Neuter Adjectives are used substantively in the following special senses:—

a. The neuter singular may denote either a single object or an abstract quality:—

• honestum, an honorable act, or virtue (as a quality).
• opus est mātūrātō, there is need of haste. [Cf. impersonal passives § 208. d.]

b. The neuter plural is used to signify objects in general having the quality denoted, and hence may stand for the abstract idea:—

• omnēs fortia laudant, all men praise bravery (brave things).

c. A neuter adjective may be used as an appositive or predicate noun with a noun of different gender (cf. § 287. a):—

• trīste lupus stabulīs (Ecl. 3.80), the wolf [is] a grievous thing for the fold.
• varium et mūtābile semper fēmina (Aen. 4.569), woman is ever a changing and fickle thing.
• malum mihi vidētur esse mors (Tusc. 1.9), death seems to me to be an evil.

d. A neuter adjective may be used as an attributive or a predicate adjective with an infinitive or a substantive clause:—

• istuc ipsum nōn esse (Tusc. 1.12), that very “not to be.”
• hūmānum est errāre, to err is human.
• aliud est errāre Caesarem nōlle, aliud nōlle miserērī; (Lig. 16), it is one thing to be unwilling that Cæsar should err, another to be unwilling that he should pity.