As soon as Cicero had become fully reconciled to Caesar in the year 46 he returned with desperate energy to his old literary pursuits. In a letter written to Varro in that year[[65]], he says "I assure you I had no sooner returned to Rome than I renewed my intimacy with my old friends, my books." These gave him real comfort, and his studies seemed to bear richer fruit than in his days of prosperity[[66]]. The tenor of all his letters at this time is the same: see especially the remaining letters to Varro and also to Sulpicius[[67]]. The Partitiones Oratoriae, the Paradoxa, the Orator, and the Laudatio Catonis, to which Caesar replied by his Anticato, were all finished within the year. Before the end of the year the Hortensius and the De Finibus had probably both been planned and commenced.
Early in the following year the Academica, the history of which I shall trace elsewhere, was written.
I have now finished the first portion of my task; I have shown Cicero as the man of letters and the student of philosophy during that portion of his life which preceded the writing of the Academica. Even the evidence I have produced, which does not include such indirect indications of philosophical study as might be obtained from the actual philosophical works of Cicero, is sufficient to justify his boast that at no time had he been divorced from philosophy[[68]]. He was entitled to repel the charge made by some people on the publication of his first book of the later period—the Hortensius—that he was a mere tiro in philosophy, by the assertion that on the contrary nothing had more occupied his thoughts throughout the whole of a wonderfully energetic life[[69]]. Did the scope of this edition allow it, I should have little difficulty in showing from a minute survey of his works, and a comparison of them with ancient authorities, that his knowledge of Greek philosophy was nearly as accurate as it was extensive. So far as the Academica is concerned, I have had in my notes an opportunity of defending Cicero's substantial accuracy; of the success of the defence I must leave the reader to judge. During the progress of this work I shall have to expose the groundlessness of many feelings and judgments now current which have contributed to produce a low estimate of Cicero's philosophical attainments, but there is one piece of unfairness which I shall have no better opportunity of mentioning
than the present. It is this. Cicero, the philosopher, is made to suffer for the shortcomings of Cicero the politician. Scholars who have learned to despise his political weakness, vanity, and irresolution, make haste to depreciate his achievements in philosophy, without troubling themselves to inquire too closely into their intrinsic value. I am sorry to be obliged to instance the illustrious Mommsen, who speaks of the De Legibus as "an oasis in the desert of this dreary and voluminous writer." From political partizanship, and prejudices based on facts irrelevant to the matter in hand, I beg all students to free themselves in reading the Academica.
II. The Philosophical Opinions of Cicero.
In order to define with clearness the position of Cicero as a student of philosophy, it would be indispensable to enter into a detailed historical examination of the later Greek schools—the Stoic, Peripatetic, Epicurean and new Academic. These it would be necessary to know, not merely as they came from the hands of their founders, but as they existed in Cicero's age; Stoicism not as Zeno understood it, but as Posidonius and the other pupils of Panaetius propounded it; not merely the Epicureanism of Epicurus, but that of Zeno, Phaedrus, Patro, and Xeno; the doctrines taught in the Lyceum by Cratippus; the new Academicism of Philo as well as that of Arcesilas and Carneades; the medley of Academicism, Peripateticism, and Stoicism put forward by Antiochus in the name of the Old
Academy. A systematic attempt to distinguish between the earlier and later forms of doctrine held by these schools is still a great desideratum. Cicero's statements concerning any particular school are generally tested by comparing them with the assertions made by ancient authorities about the earlier representatives of the school. Should any discrepancy appear, it is at once concluded that Cicero is in gross error, whereas, in all probability, he is uttering opinions which would have been recognised as genuine by those who were at the head of the school in his day. The criticism of Madvig even is not free from this error, as will be seen from my notes on several passages of the Academica[[70]]. As my space forbids me to attempt the thorough inquiry I have indicated as desirable, I can but describe in rough outline the relation in which Cicero stands to the chief schools.
The two main tasks of the later Greek philosophy were, as Cicero often insists, the establishment of a criterion such as would suffice to distinguish the true from the false, and the determination of an ethical standard[[71]]. We have in the Academica Cicero's view of the first problem: that the attainment of any infallible criterion was impossible. To go more into detail here would be to anticipate the text of the Lucullus as well as my notes. Without further refinements, I may say that Cicero in this respect was in substantial agreement with the New Academic school, and in opposition to all other schools. As he himself says, the doctrine that absolute knowledge is impossible was the one Academic tenet against which all the other schools
were combined[[72]]. In that which was most distinctively New Academic, Cicero followed the New Academy.
It is easy to see what there was in such a tenet to attract Cicero. Nothing was more repulsive to his mind than dogmatism. As an orator, he was accustomed to hear arguments put forward with equal persuasiveness on both sides of a case. It seemed to him arrogant to make any proposition with a conviction of its absolute, indestructible and irrefragable truth. One requisite of a philosophy with him was that it should avoid this arrogance[[73]]. Philosophers of the highest respectability had held the most opposite opinions on the same subjects. To withhold absolute assent from all doctrines, while giving a qualified assent to those which seemed most probable, was the only prudent course[[74]]. Cicero's temperament also, apart from his experience as an orator, inclined him to charity and toleration, and repelled him from the fury of dogmatism. He repeatedly insists that the diversities of opinion which the most famous intellects display, ought to lead men to teach one another with all gentleness and meekness[[75]]. In positiveness of assertion there seemed to be something reckless and disgraceful, unworthy of a self-controlled character[[76]]. Here we have a touch of feeling thoroughly Roman. Cicero further urges arguments similar to some put forward by a long series of English thinkers from Milton to Mill, to show that the free conflict of opinion is necessary