Grammar, like phonetics, was by the ancients often regarded as a part of “music.”[67] It would not, therefore, seem unnatural to his readers that, in a treatise on euphony, Dionysius should continually be referring to the parts of speech (τὰ μόρια τοῦ λόγου). He also uses freely such technical terms of grammar as: πτῶσις, ἔγκλισις, ἀπαρέμφατος, πληθυντικῶς, ὕπτιος, ἀρρενικός, θηλυκός, οὐδέτερος, ἄρθρον, ὄνομα, πρόθεσις, σύνδεσμος, etc. Though himself concerned more immediately with the euphonic relations of words, he is fully alive to the phenomena of their syntactical relations. His remarks on grammatical points show, as might have been expected, many points of contact with the brief treatise of another Dionysius—Dionysius Thrax, who was born a full century earlier than himself. Dionysius Thrax was a pupil of Aristarchus, and produced the earliest formal Greek Grammar. Some interesting hints as to the successive steps in grammatical analysis which had made such a Grammar possible may be found in the second chapter of the de Compositione, where special mention is made of Theodectes, Aristotle, and “the leaders of the Stoic School.” In c. 5, a useful protest is raised against the tyranny of grammar, which so often seeks to control by iron “rules” the infinite variety and living flexibility of language.
The standard edition of Dionysii Thracis Ars Grammatica is that by Uhlig (Leipzig, 1883). The whole question of ancient views on grammar can be studied in Steinthal’s Geschichte der Sprachwissenschaft bei den Griechen und Römern, mit besonderer Rücksicht auf die Logik (2nd ed., Berlin, 1890-91).