De analogia (full title: De analogia libri II ad M. Tullium Ciceronem) were the two books of a grammatical work on the Latin language written by Julius Caesar and dedicated to Cicero. Only few fragments from this important work have survived. Suetonius mentions that Caesar wrote De analogia while he and his army were crossing the Alps.
Analogia denotes the adherence to grammatical rules while not changing one's diction with current demotic usage. After the composition of his Commentarii de bello Gallico Caesar felt obligated to devise certain grammatical principles in reference to his commentaries, writing that "the choice of words is the fountain-head of eloquence." Parts of this work could have also been triggered by comments in Cicero's De oratore. Cicero himself mentioned that Caesar's De Analogia had been written with greatest accuracy.
- harena should only be used in the singular (singular form: "sand"; plural form: "grains of sand")
- quadrigae ("four-horse chariot") should only be used in the plural
- the variant Calypsonem is to be used for the declension of the latinized Greek name Καλυψώ
- turbonem is to be preferred over turbinem, where turbo means "storm"
In the ancient Latin dictionary De Verborum Significatu by Sextus Pompeius Festus, which was a new edition of Flaccus' homonymous work, Festus quotes a fragment of the De analogia in the discussion of the double consonant. Caesar limits the ancient, primitive Latin alphabet to eleven letters. A comparison with the parallel Varronian fragment however has shown that Caesar here only meant the ancient consonants.
- Gaius Iulius Caesar: fragments from De analogia libri II
- Suetonius, Julius 6.5; disputed by Marcus Cornelius Fronto in his De bello Parthico 9: Quod te vix quicquam nisi raptim et furtim legere posse prae curis praesentibus scripsisti, fac memineris et cum animo tuo cogites C. Caesarem atrocissimo bello Gallico cum alia multa militaria tum etiam duos De analogia libros scrupulosissimos scripsisse, inter tela volantia de nominibus declinandis, de verborum aspirationibus et rationibus inter classica et tubas. Translation (abridged): "Think of C. Caesar in that appalling Gallic War writing about noun declensions as weapons flew past." Contra: O.A.W. Dilke, "The Literary Output of the Roman Emperors", in: Greece & Rome IV 1, 1957
- Gaius Iulius Caesar, De Analogia Libri II, quoted in: Marcus Tullius Cicero, Brutus 253
- G.L. Hendrickson, "The De Analogia of Julius Caesar — Its Occasion, Nature and Date with Additional Framgents", in: Classical Philology, Vol. I 2, pp. 97–120
- accuratissime (Marcus Tullius Cicero, Brutus 253)
- Marcus Fabius Quintilianus thought it an archaic rule "in deference of antiquity"; in: Institutio Oratoria I.5.63
- Dilke (1957) finds this "very odd", although the form turbonem was in most frequent use in ancient Rome. The Latin word turbo is known for describing a "whirlwind" and a "tornado", the word turbedo ("storm") being a derivative.
- Sextus Pompeius Festus, De Verborum Significatu V 108.7–13, (Grammatici Latini, ed. Keil 2002)
- Alessandro Garcea, "César et l'alphabet: Un fragment du De Analogia (frg. 4 p. 148 funaioli = 5 p. 179 s. Klotz)", in: Histoire épistémologie langage, Vol. XXIV No. 2 (2002), pp. 147–164