Cato Maior, on old age; Laelius, on friendship;
De Fato, discussing Fate and Free Will;
Paradoxa, a book setting forth certain remarkable views of the Stoics;
De Officiis, a treatise on practical ethics, the application of moral principles to the questions and difficulties of ordinary life.
These works, written mostly in 45 and 44, are, except the De Cons., still extant. To the list may be added also other works of a rhetorical nature, such as the Topica and De Optima Genere Dicendi, and some lost philosophical books, such as De Gloria.
Even though allowance be made for the fact that Cicero was giving in Latin the substance of Greek books with which he had been familiar from boyhood, the mental vigor and literary power exhibited by this series of works appear prodigious when we consider their great compass and variety and the generally high finish of their style.
References.—For a fuller account of Cicero's philosophical views and writings consult Ritter, 'History of Ancient Philosophy', Vol. 4, Ch. 2; Maurice, 'Moral and Metaphysical Philosophy', Ch. 7, § 5; Tennemann and Morell, 'History of Philosophy', Ch. 3; Ueberweg, 'History of Philosophy', Vol I, § 61; J.B. Mayor, 'Sketch of Ancient Philosophy', pp. 223-244; Teuffel, 'History of Roman Literature', Vol. i, § 172 et seq. Cruttwell, 'History of Roman Literature', Bk. II. Part 1, Ch. 2; 'Cicero', by Collins, in Ancient Classics for English Readers, Ch. 10, et seq.; also the Introduction to Reid's edition of the Academica, and the account of Cicero by Prof. Ramsay in Smith's Dictionary of Biography and Mythology. The most attractive biography of Cicero in English is that by Forsyth. That by Trollope is able but quite partisan. On the philosophy, consult also Zeller's 'Eclectics.'