179. Where the genitive with a preposition is not ablatival, it may usually be explained in twο ways, between which it is not always easy to choose.
- It may be derived from one of the uses with verbs discussed in §§ 149-151. e. g.the genitive in
ὅς τʼ εἶσιν διὰ δουρός
which gοes through the wοοdis probably the genitive of the space within which motion takes place. For εἶσιν διὰ δουρός has the same relation to πεδίοιο διώκειν and πεδίοιο διαπρήσσειν, that ἦλθεν εἰς Τροίην has to Τροίην ἦλθεν and Τροίην εἰσῆλθεν.
- It may be of the same kind as the genitive with a noun: e. g. the construction with ἀντί may be the same as with the adverbs ἄντα, ἀντίον, ἀντία, etc., and the adjectives ἀντίος, ἐναντίος, etc., and this is evidently not akin to any of the constructions with verbs, but falls under the general rule that a noun or pronoun qualifying a noun is put in the genitive (§ 147).
It is held by Curtius (Elucidations, c. 17) that the genitive with ἀντί, πρό, διά, ὑπέρ, ὑπό, when they do not necessarily imply mοtίοn from, is of the same kind as the ordinary genitive with adjectives and adverbs, i. e. the true genitive. This view is supported by the improper prepositions, which nearly all govern the genitive, whatever their meaning: e. g. ἐγγύς and ἑκάς, ἐντός and ἐκτός, ἄντα, μέχρι, ἕνεκα, etc. For in these cases the construction evidently does not depend upon the local relation involved, but is of the same kind as in δέμας πυρός, χάριν Τρώων, etc.
On the other hand, it is pointed out by Delbrück (Synt. Forsch. iv. p. 134) that such a construction of the genitive is unknown in Sanskrit, and this argument, which applies to πρό, ὑπό, ὑπέρ (Sanskrit prá, úpa, uρári), is confirmed by the Latin construction of pro, sub, super with the ablative. He wοuld allow the supposition however in the case of ἀντί (the Sanskrit ánti being an adverb), and perhaps διά; regarding these words as having become prepοsitions more recently than the others.