It was about this time that Cicero was especially courted by the heads of the dictator's party, of whom Hirtius and Dolabella went so far as to declaim daily at his house for the benefit of his instructions.[220] A visit of this nature to the Tusculan villa, soon after the publication of the De Finibus, gave rise to his work entitled Tusculanæ Quæstiones, which professes to be the substance of five philosophical disputes between himself and friends, digested into as many books. He argues throughout after the manner of an Academic, even with an affectation of inconsistency; sometimes making use of the Socratic dialogue, sometimes launching out into the diffuse expositions which characterise his other treatises.[221] He first disputes against the fear of death; and in so doing he adopts the opinion of the Platonic school, as regards the nature of God and the soul. The succeeding discussions on enduring pain, on alleviating grief, on the other emotions of the mind, and on virtue, are conducted for the most part on Stoical principles.[222] This is a highly ornamental composition, and contains more quotations from the poets than any other of Cicero's treatises.
We have already had occasion to remark upon the singular activity of his mind, which becomes more and more conspicuous as we approach the period of his death. During the ensuing year, which is the last of his life, in the midst of the confusion and anxieties consequent on Cæsar's death, and the party warfare of his Philippics, he found time to write the De Naturâ Deorum, De Divinatione, De Fato, De Senectute, De Amicitiâ, De Officiis, and Paradoxa, besides the treatise on Rhetorical Common Places above mentioned.
Of these, the first three were intended as a full exposition of the conflicting opinions entertained on their respective subjects; the De Fato, however, was not finished according to this plan.[223] His treatise De Naturâ Deorum, in three books, may be reckoned the most splendid of all his works, and shows that neither age nor disappointment had done injury to the richness and vigour of his mind. In the first book, Velleius, the Epicurean, sets forth the physical tenets of his sect, and is answered by Cotta, who is of the Academic school. In the second, Balbus, the disciple of the Porch, gives an account of his own system, and is, in turn, refuted by Cotta in the third. The eloquent extravagance of the Epicurean, the solemn enthusiasm of the Stoic, and the brilliant raillery of the Academic, are contrasted with extreme vivacity and humour;—while the sublimity of the subject itself imparts to the whole composition a grander and more elevated character, and discovers in the author imaginative powers, which, celebrated as he justly is for playfulness of fancy, might yet appear more the talent of the poet than the orator.
His treatise De Divinatione is conveyed in a discussion between his brother Quintus and himself, in two books. In the former, Quintus, after dividing Divination into the heads of natural and artificial, argues with the Stoics for its sacred nature, from the evidence of facts, the agreement of all nations, and the existence of divine intelligences. In the latter, Cicero questions its authority, with Carneades, from the uncertain nature of its rules, the absurdity and uselessness of the art, and the possibility of accounting from natural causes for the phenomena on which it was founded. This is a curious work, from the numerous cases adduced from the histories of Greece and Rome to illustrate the subject in dispute.
His treatise De Fato is quite a fragment; it purports to be the substance of a dissertation in which he explained to Hirtius (soon after Consul) the sentiments of Chrysippus, Diodorus, Epicurus, Carneades, and others, upon that abstruse subject. It is supposed to have consisted at least of two books, of which we have but the proem of the first, and a small portion of the second.
In his beautiful compositions, De Senectute and De Amicitiâ, Cato the censor and Lælius are respectively introduced, delivering their sentiments on those subjects. The conclusion of the former, in which Cato discourses on the immortality of the soul, has been always celebrated; and the opening of the latter, in which Fannius and Scævola come to console Lælius on the death of Scipio, is as exquisite an instance of delicacy and taste in composition as can be found in his works. In the latter he has borrowed largely from the eighth and ninth books of Aristotle's Ethics.
His treatise De Officiis was finished about the time he wrote his second Philippic, a circumstance which illustrates the great versatility of his mental powers. Of a work so extensively celebrated, it is enough to have mentioned the name. Here he lays aside the less authoritative form of dialogue, and, with the dignity of the Roman Consul, unfolds, in his own person, the principles of morals, according to the views of the older schools, particularly of the Stoics. It is written in three books, with great perspicuity and elegance of style; the first book treats of the honestum, or virtue, the second of the utile, or expedience, and the third adjusts the claims of the two, when they happen to interfere with each other.
His Paradoxa Stoicorum might have been more suitably, perhaps, included in his rhetorical works, being six short declamations in support of the positions of Zeno; in which that philosopher's subtleties are adapted to the comprehension of the vulgar, and the events of the times. The second, fourth, and sixth, are respectively directed against Antony, Clodius, and Crassus. They seem to have suffered from time.[224] The sixth is the most eloquent, but the argument of the third is strikingly maintained.
Besides the works now enumerated, we have a considerable fragment of his translation of Plato's Timæus, which he seems to have finished in his last year. His remaining philosophical works, viz.: the Hortensius, which was a defence of philosophy; De Gloriâ; De Consolatione, written upon Platonic principles on his daughter's death; De Jure Civili, De Virtutibus, De Auguriis, Chorographia, translations of Plato's Protagoras, and Xenophon's Œconomics, works on Natural History, Panegyric on Cato, and some miscellaneous writings, are, except a few fragments, entirely lost.