Horace is most well known for his Ars Poetica (Art of Poetry). He lived during the 1st century BCE and, unlike Plato, see more value in poetry than Plato. Here, I will briefly lay out a few observations of Horace’s Ars Poetica which stood out to me.
First, Horace’s understanding of genre is much more theoretical and developed than Aristotle and Plato. Recall that Aristotle and Plato had relatively rigid understandings of genre. Though not commenting explicitly on genre, Horace’s comments on speech and expression can be applied to genre as well: “Many terms shall grow back which now have fallen away, and those now held in esteem shall fall, if our poetic practices so approves. Such is the criterion by which judgement, rules and standards for speech expression are to be discovered” . Expressed another way, Horace at least recognizes that genre conventions change over time, often the result of critical reflections.
Second, one way modern scholars have approached genre is by thinking of genre as a simulated speech situation . Horace supports this notion inasmuch as he recognizes that the speaker portrayed in a text should be understood in light of his/her social circumstances: “If a speaker’s words are not constant with his fortunes, the people (both horse and foot) will burst out laughing! It will make a lot of difference whether a god is speaking or a hero; a mature old man or one still in flower of youth; a strong-minded dame or a busy nurse, a far-travelled merchant or a cultivator of a green farm, a Colchian or Assyiran, or someone reared at Thebes or Argos” .
In other words, the audience has certain assumptions of a speaker. As such, the speaker and speech must align with each other so that the social circumstances of the speaker fit with the speech itself. When these do not align, the audience laughs! At base, then, the speaker of a situation impacts how the audience interprets and understands the speech. This is akin to genre: the genre designation of a text impacts how the audience interprets and understands the speech.
Third, and finally, Horace’s understanding of genres is based on an evolutionary model, akin to Aristotle. Here, he offers a historiography of the origins of Greek genres: “They say the unknown genre of the tragic muse was discovered by Thespis, who wheeled his poems about on wagons for men to sing and act, their faces well stained with lees. After him, as inventor of the mask and the noble robe, Aeschylus laid out a stage with modest sized beams, producing plays which resounded grandly and strode on the buskin” .
His observations are important on a few fronts. First, he views genres in the same vein as Aristotle, slowly developing over time and becoming more and more refined. This notion is still present in modern discourse about genre, especially with the appearance of the modern novel. Second, though no surprise, Horace’s historiography of genres is directed related to materiality and social situation. As such, it suggests that any understanding of genre or genre development must also be conscious of materiality and social situation.
 The Norton Anthology of Theory and Criticism, 135.
 Simeon Chavel, “Knowledge of the Lord in the Hebrew Bible,” in KNOW Vol. 2, No. 1 (2018), 48-49.
 The Norton Anthology of Theory and Criticism, 136.
 The Norton Anthology of Theory and Criticism, 139.