Or hear'st thou (cluis, Lat.) rather pure ethereal stream,
Whose fountain who (no one) shall tell?—Paradise Lost.
CHAPTER XXVIII.
ON THE CASE ABSOLUTE.
[§ 519]. Broadly speaking, all adverbial constructions are absolute. The term, however, is conveniently limited to a particular combination of the noun, verb, and participle. When two actions are connected with each other, either by the fact of their simultaneous occurrence, or as cause and effect, they may be expressed within the limits of a single proposition, by expressing the one by means of a verb, and the other by means of a noun and participle agreeing with each other. The door being open, the horse was stolen.
Considering the nature of the connection between the two actions, we find good grounds for expecting à priori that the participle will be in the instrumental case, when such exists in the language: and when not, in some case allied to it, i.e., the ablative or dative.
In Latin the ablative is the case that is used absolutely. Sole orto, claruit dies.
In Anglo-Saxon the absolute case was the dative. This is logical.