On the Sublime is an essential compedium of ancient literary esthetics. In Chapter 8, he gives the five sources of sublimity:
1- Ability to form grand conceptions
2- The stimulus of powerful and sublime emotions
3- Proper formation of figures of thought
4- Proper formation of figures of speech (noble diction - choice of words, use of imagery, elaboration of style)
5- Total effects resulting from dignity and grandeur
In chapter 13, he extolls the literary merit of Plato:
And it seems to me that there would not have been so fine a bloom of perfection on Plato's philosophical doctrines, and that he would not in many cases have found his way to poetical subject-matter and modes of expression, unless he had with all his heart and mind struggled with Homer for the primacy, entering the lists like a young champion matched against the man whom all admire, and showing perhaps too much love of contention and breaking a lance with him as it were, but deriving some profit from the contest none the less.
In Chapters 35 & 36, he develops a semi-platonic conception of esthetics:
This besides many other things, that Nature has appointed us men to be no base nor ignoble animals; but when she ushers us into life and into the vast universe as into some great assembly, to be as it were spectators of the mighty whole and the keenest aspirants for honour, forthwith she implants in our souls the unconquerable love of whatever is elevated and more divine than we.
36. In statues likeness to man is the quality required; in discourse we demand, as I said, that which transcends the human. 4. Nevertheless--and the counsel about to be given reverts to the beginning of our memoir--since freedom from failings is for the most part the successful result of art, and excellence (though it may be unevenly sustained) the result of sublimity, the employment of art is in every way a fitting aid to nature; for it is the conjunction of the two which tends to ensure perfection.
