The criticism of a classical author with a view to establish a sound and defensible text is of two kinds, each of which supplements and aids the other. The first is Diplomatic Criticism, which has to do with the age, authenticity, and value of the existing manuscripts (diplomata); and the second is Verbal or Grammatical Criticism, which alters the text in order to make it conform to good sense or to the laws of the language, or to the critic's conception of what the author meant to say. The former is based upon Palaeography; the second in part upon the science of Philology and in part upon aesthetic principles. Wolff and Boeckh classified the former as “Superior” criticism, and the latter as “Inferior,” but this terminology is not generally accepted. The best text-critic is he who can bring to bear upon his task a minute palaeographical knowledge and at the same time linguistic training and a sound literary sense.

Textual criticism in Greece originated in the necessity that was felt of a unification and collation of the various versions of the Homeric poems. Homer was to the Greeks much more than a poet; he was long regarded as a great teacher of practical and also of ethical wisdom, and he was read and studied in the schools in much the same spirit as a Christian would study the Bible, or a Mohammedan the Korân. Owing to the fact that the Homeric poems were largely transmitted orally and to the additional fact that the rhapsodists who recited them in public frequently altered the text to suit the special occasion or their own notion of an effective arrangement, there were many versions current even in very early times. It has been inferred that Solon took some steps toward the establishing of an Homeric canon (Plato, Hipparch.228B; Diog. Laert.i. 57), and Pisistratus and his son Hipparchus are said to have intrusted a recension of the text to a commission of four scholars who were to edit and unify the poems. This recension is thought to have formed the basis of the famous “City Editions” (q. v.) which in turn were worked over by the Alexandrian scholars. Other special texts were made by Theagenes of Rhegium, Stesimbrotus of Thasos (c. 450 B.C.), and by Aristotle, who prepared a version for the use of his pupil Alexander the Great, usually called ἡ ἐκ νάρθηκος from the case in which it was kept ( Plut. Alex.8; cf. Cope's introduction to Aristotle's Rhetoric). Demetrius Phalereus also edited the Iliad and the Odyssey, while the Sophists spent considerable time in the critical study of Homer. (See Friedel, De Sophistarum Studiis Homericis [Halle, 1873]). At about this time criticism was also applied to the texts of other great writers—to those of Aeschylus, Sophocles, and Euripides—of whom an authentic text was promulgated by the orator and statesman Lycurgus, about B.C. 350, which was the only one allowed to be used by the actors. (See Korn, De Aeschyli, Sophoclis, Euripidis Fabularum Exemplari Lycurgo Auctore Confecto [Bonn, 1863].) Commentaries were also written on special points by the Stoics and by the Cynics.

A more definite and scientific criticism was that undertaken by the philological section of the School at Alexandria (see Alexandrian School), and in connection with the great Alexandrian Library (see Bibliotheca), for which great quantities of manuscripts were purchased by King Ptolemy at the advice of Demetrius Phalereus. All of the early heads of the School worked at text-recension. Zenodotus of Ephesus (B.C. 325-260) published a collection of Homeric glosses (see Glossa), and about B.C. 274 put forth a διόρθωσις or recension of both the Iliad and the Odyssey, also called the ἔκδοσις Ὁμήρου. In this, four kinds of corrections appear: (a) Elimination or the omission of lines known to be spurious; (b) Query or the indication of doubtful lines; (c) Transposition or a change in the order of the lines; and (d) Emendation or the substitution of new readings for the old. See Düntzer, De Zenodoti Studiis Homericis (Göttingen, 1848).

The existing texts were classified and characterized in the Πίνακες of Callimachus, the first great bibliographical work ever written; and Eratosthenes of Cyrené wrote a critical treatise on the poets of the Old Comedy. He was succeeded by Aristophanes of Byzantium , perhaps the greatest philologist of antiquity. His criticism was partly diplomatic and partly verbal; and was guided always by the sentiment critique. He did much for both text-criticism and for language-study in general. To him is ascribed the invention of diacritical marks and symbols (σημεῖα κριτικά), all of great palaeographic importance. Ten of these are known as the δέκα προσῳδίαι: (a) the rough breathing (πνεῦμα δασύ); (b) the smooth breathing (πνεῦμα ψιλόν); (c) the grave accent (βαρεῖα); (d) the acute accent (ὀξεῖα); (e) the circumflex accent (τόνος ὀξυβαρεῖα or περισπωμένη); (f and g) the long and short marks (χρόνοι); (h) the διαστολή or comma (virgule); (i) the hyphen (ὑφέν); (j) the apostrophe (ἀπόστροφος). The Greek marks of punctuation are also ascribed to Aristophanes. His critical work included an edition of Homer (a second διόρθωσις), and also editions of Hesiod (the Theogony), Alcaeus, Anacreon, Pindar, Euripides, Aristophanes, and perhaps Simonides and Menander. The famous Alexandrian Canon was in part his work. See Canon Alexandrinus.

His great pupil Aristarchus of Samothrace (c. 217-143 B.C.) did much for the study of formal grammar (see Grammatica), and also edited Archilochus, Alcaeus, Hesiod, Pindar, Aeschylus, Sophocles, Aristophanes, and especially the Homeric poems, of which he put forth two separate recensions, writing συγγράμματα or special monographs, besides the ἐκδόσεις (texts) and ὑπομνήματα (commentaries). Aristarchus approached his task in a skeptical spirit, and employed five processes: (a) διόρθωσις or arrangement of the text; (b) ἀνάγνωσις or determination of accents; (c) τέχνη, determination of forms and questions of syntax; (d) ἐξήγησις or explanation of words, allusions, etc.; and (e) κρίσις, the determination of all questions respecting authenticity or integrity of the text, and the final judgment of the author as a whole. Aristarchus used a number of critical symbols in his work. Among them were the ὀβελός or spit (—) to mark a spurious line; the διπλῆ to call attention to some special point; the dotted διπλῆ to denote a variant from the reading of Zenodotus; and the ἀστέρισκος (*) to denote a “formulaic” line. Of the 15,600 lines of the Iliad and Odyssey, Aristarchus “athetized,” i. e. struck out as spurious, 1160.

The later Alexandrians did also much careful work in the recension of texts, and so did the rival School of Pergamus, headed by Crates of Mallos, the “Anomalist” (see Crates; Philologia), who flourished in B.C. 168. Didymus Chalcenteros is the last of the important Greek text critics.

From the Greeks the Romans received the principles of textual criticism, and early began to apply these principles to the study of Latin works. Lucius Aelius Stilo investigated the text of the Carmina Saliaria; M. Antonius Griphus wrote commentaries on the Annales of Ennius. Cicero is said to have prepared an edition of Lucretius. (See Lucretius.) To Varro we owe the establishment of a Plautine Canon. (See Plautus; Varro.) The greatest of the Roman text-critics was M. Valerius Probus Berytus (c. 80 A.D.), who edited, with critical signs, Vergil, Horace, Lucretius, and Terence, and wrote a treatise on the σημεῖα κριτικά. (See Suet. Reliq. p. 138, Reifferscheid; and the introduction to Conington's Vergil, i. pp. lxv. foll.) Glossography also flourished greatly among the Romans. See Glossa; Scholia ; Subscriptio.

In the first period of the Renaissance in Italy the study of texts revived during the corruption of existing manuscripts. (See Renaissance.) Among these early critics are Laurentius Valla (q.v.) and Politianus (q.v.). The critical acumen of scholars was much sharpened by the immense number of forged texts that began to appear. A single forger, Annius of Viterbo, alone put forth seventeen volumes of spurious works ascribed by him to the classical writers. (See Wachler in Ersch and Gruber's Encyclopädie.) Gradually a scientific basis for textual criticism was established, the great names in this process being those belonging to the so-called French or Polyhistorical School, the Scaligers, Lambinus, Salmasius, and Casaubon; and to the Anglo-Dutch or Critical School, Gronovius, Burmann, Hemsterhuys, and especially Richard Bentley.

Text-critics are generally to be classified according to the relative importance which they give to the subjective element in their criticism. Bentley, who is the father of the subjective method, in his later work largely disregarded the evidence of manuscripts in his determination of the proper lections, depending largely upon his own instinctive feeling as to what an author must have said. He has expressed this principle in a formal phrase —Nobis et ratio et res ipsa centum codicibus potiores sunt—and in following this out he did much that was rash and indefensible as well as much that is brilliant and convincing. The reductio ad absurdum of this subjective method will be found in Bentley's edition of Milton's Paradise Lost, in which he rewrote whole passages, because of reasons based on his own conception of what Milton must in reality have said.

The school that represents the antithesis of the Bentleian principle is that of which the Jesuit scholars of France stand as a type. These held to what they called la tradition classique, and studied to avoid any radical changes in a text whatever, going so far as to force an explanation of passages that evidently violate the laws of the ancient languages, history, and good sense. The Bentleians rewrite everything; the other school explains everything; and each set must be regarded as often equally unreasonable.