[1369.] The substantive of the ablative absolute usually denotes a different person or thing from any in the main sentence. But exceptions to this usage sometimes occur: as,
quibus audītīs, eōs domum remittit, 4, 21, 6, after listening to these men, he sends them home again. sī ego mē sciente paterer, Pl. MG. 559, if I should wittingly myself allow, more emphatic than sciēns. sē iūdice nēmo nocēns absolvitur, J. 13, 2, himself the judge, no criminal gets free.
[1370.] Two ablatives absolute often occur together, of which the first indicates the time, circumstances, or cause of the second: as, exaudītō clāmōre perturbātīs ōrdinibus, 2, 11, 5, the ranks being demoralized from hearing the shouts. cōnsūmptīs omnibus tēlīs gladiīs dēstrictīs, Caes. C. 1, 46, 1, drawing their swords after expending all their missiles.
[1371.] The substantive is sometimes omitted in the ablative absolute, particularly when it is a general word for a person or a thing which is explained by a relative: as, praemissīs, quī repūrgārent iter, L. 44, 4, 11, sending sappers and miners ahead to clear a way. relātīs ōrdine, quae vīdissent, L. 42, 25, 2, telling circumstantially all they had seen.
[1372.] The ablative neuter of some perfect participles is used impersonally ([1034]). This use is rare in old Latin, in classical Latin commonest in Cicero, and afterwards in Livy: as, auspicātō, DN. 2, 11, with auspices taken. sortītō, V. 2, 126, lots being drawn, or by lot. Such ablatives readily become adverbs ([704]). Substantives are also sometimes used alone: as, austrō, Div. 2, 58, when the wind is south. tranquillitāte, Plin. Ep. 8, 20, 6, when it is calm. serēnō, L. 37, 3, 3, the day being clear.
[1373.] The ablative neuter of some perfect participles is occasionally used in agreement with a sentence or an infinitive: as, cōgnitō vīvere Ptolomaeum, L. 33, 41, 5, it being known that Ptolomy was alive. This construction is not used in old Latin, and is rare in classical Latin, but common in Livy and Tacitus. So adjectives also: as, incertō quid vītārent, L. 28, 36, 12, it not being obvious what they were to steer clear of.
[1374.] The ablative absolute is sometimes attended, especially in Livy and Tacitus, by an explanatory word, such as etsī, tamen, nisi, quasi, quamquam, or quamvīs: as, etsī aliquō acceptō dētrīmentō, tamen summā exercitūs salvā, Caes. C. 1, 67, 5, though with some loss, yet with the safety of the army as a whole.
[1375.] The ablative with an adjective in agreement or with a limiting genitive is used to denote quality, either predicatively or attributively: as,