1. _De Re Publica_, a discussion of the ideal state and the ideal citizen, was published before B.C. 51, for Caelius writes to Cicero in Cilicia, 'tui politici libri omnibus vigent' (_ad Fam._ viii. 1, 4). In this treatise Cicero made use of Plato, and of Aristotle, Theophrastus, and other Peripatetics (_de Div._ ii. 3). There were six Books; but until 1822 the _Somnium Scipionis_, extracted by Macrobius from Book vi., was the only portion of the work known to exist, with the exception of a few fragments. In that year Mai published at Rome, from a Vatican palimpsest, remains which make up about one-third of the whole. 2. The _De Legibus_ succeeded the _De Re Publica_, as Plato's _Laws_ came after the _Republic_. The speakers in this dialogue are Atticus, Cicero, and his brother Quintus. Book i. expounds the Stoic position that the laws of the ideal state are made by the wise man in accordance with the mind of God; this position is worked out in Book ii. in the regulations for religion, and in iii. on the duties of magistrates. The treatise was never completed, and was perhaps a posthumous publication: it is not mentioned in the list in _De Divinatione_ ii. 1-3, and there is no preface, though Cicero says (_ad Att._ iv. 16, 2) 'in singulis libris utor prooemiis.' Certainly it had not appeared in B.C. 46, the year of the _Brutus_ (_Brut._ 19). It was composed after the murder of Clodius in January, B.C. 52 (ii. 42), and in Pompey's lifetime (iii. 22): probably in 52, as the government of Cilicia and the civil war left Cicero no time for literature during the years 51-48. 3. In the spring of 46 was written the short tract _Paradoxa_, a discussion of six Stoic paradoxes (_e.g._ that the wise man alone is free). It was addressed to Brutus, and was later than the dialogue which bears his name; cf. the preface, 'accipies hoc parvum opusculum, lucubratum his iam contractioribus noctibus, quoniam illud maiorum vigiliarum munus in tuo nomine apparuit.' 4. The death of Tullia in February, 45, led Cicero to write, at Astura, a _Consolatio_, of which only fragments survive. Plin. _N.H._ praef. 22, quotes Cicero as saying that he here followed the Greek philosopher, Crantor, περὶ πένθους. It contained notices of the deaths of great men, _De Div._ ii. 22, 'clarissimorum hominum nostrae civitatis gravissimos exitus in Consolatione collegimus.' 5. In the _Hortensius_ Cicero appeared as the champion of philosophy: _De Fin._ i. 2, 'philosophiae vituperatoribus satis responsum est eo libro, quo a nobis philosophia defensa et collaudata est, cum esset accusata et vituperata ab Hortensio.' It cannot be traced beyond the seventh century, and is now represented by a few fragments. In the Middle Ages it was confounded with the _Prior Academics_, the speakers in both dialogues being the same. The _Hortensius_ seems to have been written before Cicero went to Astura in March, B.C. 45: there is no allusion to it in his letters.