418. The Ablative of Specification denotes that in respect to which anything is or is done.
Virtūte praecēdunt. (B. G. 1.1)
They excel in courage.
claudus alterō pede (Nep. Ages. 8)
lame of one foot
linguā haesitantēs, vōce absonī (De Or. 1.115)
hesitating in speech, harsh in voice
Sunt enim hominēs nōn rē sed nōmine. (Off. 1.105)
For they are men not in fact, but in name.
cf. § 131.c)
paulum aetāte prōgressī (Cat. M. 33)
somewhat advanced in age
Corpore senex esse poterit, animō numquam erit. (id. 38)
He may be an old man in body, he never will be [old] at heart.
a. To this head are to be referred many expressions where the ablative expresses that in accordance with which anything is or is done.
with perfect right
in my fashion
in my opinion
But also more formally, ex meā sententiā
[Here the sense is the same, but the first ablative is specification, the second source.]
propinquitāte coniūnctōs atque nātūrā (Lael. 50)
closely allied by kindred and nature
[Here the ablative is not different in sense from those above, but no doubt is a development of means.]
quī vincit vīribus (id. 55)
who surpasses in strength
[Here it is impossible to tell whether vīribus is the means of the superiority or that in respect to which one is superior.]
Note— As the Romans had no such categories as we make, it is impossible to classify all uses of the Ablative. The Ablative of Specification (originally instrumental) is closely akin to that of manner, and shows some resemblance to means and cause. For the supine in -ū as an Ablative of Specification, see § 510.
b. The adjectives dīgnus and indīgnus take the ablative.
vir patre, avō, mâiōribus suīs dīgnissimus (Phil. 3.25)
a man most worthy of his father, grandfather, and ancestors
Tē omnī honōre indīgnissimum iūdicāvit. (Vat. 39)
He judged you entirely unworthy of every honor.
Note 1— So the verb dīgnor in poetry and later prose
Haud equidem tālī mē dīgnor honōre. (Aen. 1.335)
I do not deem myself worthy of such an honor.
Note 2— Dīgnus and indīgnus sometimes take the Genitive in colloquial usage and in poetry.
cūram dīgnissimam tuae virtūtis (Balbus in Att. 8.15)
care most worthy of your noble character
dīgnus salūtis (Plaut. Trin. 1153)
worthy of safety
māgnōrum haud umquam indīgnus avōrum (Aen. 12.649)
never unworthy of my great ancestors.