We possess a treatise, which bears the title the writer of which, as we gather from his own statement (lib. iv. praef.), during a portion of his life, practised as a forensic pleader, but abandoned the profession in disgust. The production named above is a formal introduction to judicial astrology, according to the discipline of the Egyptians and Babylonians, as expounded by the most renowned masters, among whom we find enumerated Petosiris, Necepso, Abraham, and Orpheus. The first book is chiefly occupied with a defence of the study; the second, third, and fourth contain the definitions and maxims of the science, while in the remainder the powers and natal influences (apotelesmata) of the heavenly bodies in their various aspects and combinations are fully developed, the horoscopes of Oedipus, Paris, Homer, Plato, Archimedes, and various other remarkable individuals, being examined, as examples of the propositions enunciated.

It would appear that the task was commenced towards the close of the reign of Constantine the Great, for a solar eclipse, which happened in the consulship of Optatus and Paullinus, A. D. 334, is spoken of (lib. 1.1.) as a recent event. It seems probable, however, that the whole was not published at once; for while each book is formally addressed to Manutius Lollianus, the title of proconsul is added to his name in the dedication to the last four only. If this Lollianus be the Fl. Lollianus who appears in the Fasti along with Fl. Arbitio, in the year 355, the conclusion of the work might be referred to an epoch somewhat later than this date.

Although we can trace in several passages a correspondence with the of Manilius, we are led to suppose that Firmicus was ignorant of the existence of that poem; for his expressions on two occasions (lib. ii. Praef. 8.2) imply his belief that scarcely any Roman writers had touched upon these themes except Cicero and Caesar, the translators of Aratus, and Fronto, who had followed the of Hipparchus, but had erred in presupposing a degree of knowledge on the part of his readers that they were little likely to possess. In the we find references to other pieces previously composed by the author upon similar topics, especially to a dissertation De Domino Geniturae et Chronocratone, and De Fine Vitae ; the former addressed to a friend, Murinus (4.14, 7.6.), while he promises to publish " twelve books" as a supplement to his present undertaking (5.1), together with an explanation of the (viii. Praef.), and a translation of Necepso upon health and disease (8.3). Of these not one has been preserved.

In the year 1562 Matthias Flaccius published at Strasburg, from a Minden MS., now lost, a tract bearing the title No ancient authority makes any mention of this piece, nor does it contain any allusions from which we might draw an inference with regard to the personal history of the composer. The supposition, at one time generally admitted, that he was the same person with the astrologer spoken of above, rests upon no proof whatever except the identity of name, while it is rendered highly improbable by several considerations, and is much shaken by a chronological argument. For, as we have already seen, the were certainly not commenced until after A. D. 334, and in all likelihood not finished for a considerable period; it being evident, moreover, from the spirit which they breathe, that the writer was not a Christian; while, on the other hand, the attack upon the heathen gods must have been drawn up before A. D. 350, since in that year Constans, one of the emperors, to whom it is inscribed, was slain.

The object of the essay is not so much to enlarge upon the evidences of the true faith as to demonstrate the falsehood of the different forms of pagan belief, to trace the steps by which men fell away from the service of the true God, first by personifying the powers of nature, and then by proceeding to raise mere men to the rank of divinities. In this portion of the argument the theory of Euhemerus [EUHEMERUS], which ever since the days of Ennius had exercised great influence over the Roman mind, is followed out, and the discussion concludes with an exhortation to the heathen to abandon such a system of worship, and with an appeal to the emperors, urging them to take the sternest measures for the extirpation of idolatry.