Besides speeches, which were part of his public life, he showed a deep interest in science. He wrote a treatise on grammar, _de Analogia_, for which he found time in the midst of one of his busiest campaigns [47] and dedicated to Cicero, [48] much to the orator's delight. In the dedication occur these generous words, "If many by study and practice have laboured to express their thoughts in noble language, of which art I consider you to be almost the author and originator, it is our duty to regard you as one who has well deserved of the name and dignity of the Roman people." The treatise was intended as an introduction to philosophy and eloquence, and was itself founded on philosophical principles; [49] and beyond doubt it brought to bear on the subject that luminous arrangement which was inseparable from Caesar's mind. Some of his conclusions are curious; he lays down that the genitive of _dies_ is _die_; [50] the genitive plural of _panis, pars; panum, partum_; [51] the accusative of _turbo, turbonem_; [52] the perfect of _mordeo_ and the like, _memordi_ not _momordi_; [53] the genitive of _Pompeius, Pompeiii_. [54] The forms _maximus, optimus, municipium_, [55] &c. which he introduced, seem to have been accepted on his authority, and to have established themselves finally in the language. As chief pontifex he interested himself with a digest of the _Auspices_, which he carried as far as sixteen books. [56] The _Auguralia_, which are mentioned by Priscian, are perhaps a second part of the same treatise. He also wrote an essay on _Divination_, like that of Cicero. In this he probably disclosed his real opinions, which we know from other sources were those of the extremest scepticism. There seemed no incongruity in a man who disbelieved the popular religion holding the sacred office of pontifex. The persuasion that religion was merely a department of the civil order was considered, even by Cicero, to absolve men from any conscientious allegiance to it. After his elevation to the perpetual dictatorship he turned his mind to astronomy, owing to the necessities of the calendar; and composed, or at least published, several books which were thought by no means unscientific, and are frequently quoted. [57] Of his poems we shall speak in another place. The only remaining works are his two pamphlets against Cato, to which Juvenal refers: [58] "Maiorem quam sunt duo Caesaris Anticatones." These were intended as a reply to Cicero's laudatory essay, but though written with the greatest ability, were deeply prejudiced and did not carry the people with them. [59] The witty or proverbial sayings of Caesar were collected either during his life, or after his death, and formed an interesting collection. Some of them attest his pride, as "_My word is law_;" [60] "_I am not king, but Caesar_;" [61] others his clemency, as, "_Spare the citizens_;" [62] others his greatness of soul, as, "_Caesar's wife must be above suspicion_." [63]