The Alexandrian literature was based on the decline of the pure Hellenic idiom, which from the time of Alexander the Great was superseded in daily life by an inferior jargon deriving its origin from the contact of the Macedonian dialect with various Greek and barbarian tribes; or, to speak more accurately, the Alexandrian literature sprang out of the ruin of the Hellenic nation generally, which had to perish, and did perish, in its national individuality in order to establish the universal monarchy of Alexander and the empire of Hellenism.

Had Alexander's universal empire continued to subsist, the former national and popular literature would have been succeeded by a cosmopolitan literature Hellenic merely in name, essentially denationalized and called into life in a certain measure by royal patronage, but at all events ruling the world; but, as the state of Alexander was unhinged by his death, the germs of the literature corresponding to it rapidly perished.
Nevertheless the Greek nation with all that it had possessed-- with its nationality, its language, its art--belonged to the past.
It was only in a comparatively narrow circle not of men of culture-- for such, strictly speaking, no longer existed--but of men of erudition that the Greek literature was still cherished even when dead; that the rich inheritance which it had left was inventoried with melancholy pleasure or arid refinement of research; and that, possibly, the living sense of sympathy or the dead erudition was elevated into a semblance of productiveness.

This posthumous productiveness constitutes the so-called Alexandrinism.
It is essentially similar to that literature of scholars, which, keeping aloof from the living Romanic nationalities and their vulgar idioms, grew up during the fifteenth and sixteenth centuries among a cosmopolitan circle of erudite philologues--as an artificial aftergrowth of the departed antiquity; the contrast between the classical and the vulgar Greek of the period of the Diadochi is doubtless less strongly marked, but is not, properly speaking, different from that between the Latin of Manutius and the Italian of Macchiavelli.
The Roman Alexandrinism Italy had hitherto been in the main disinclined towards Alexandrinism.
Its season of comparative brilliance was the period shortly before and after the first Punic war; yet Naevius, Ennius, Pacuvius and generally the whole body of the national Roman authors down to Varro and Lucretius in all branches of poetical production, not excepting even the didactic poem, attached themselves, not to their Greek contemporaries or very recent predecessors, but without exception to Homer, Euripides, Menander and the other masters of the living and national Greek literature.

Roman literature was never fresh and national; but, as long as there was a Roman people, its authors instinctively sought for living and national models, and copied, if not always to the best purpose or the best authors, at least such as were original.

The Greek literature originating after Aexander found its first Roman imitators--for the slight initial attempts from the Marian age( 7) can scarcely be taken into account--among the contemporaries of Cicero and Caesar; and now the Roman Alexandrinism spread with singular rapidity.
In part this arose from external causes.