Reddit mentions of Poetics. English

If anybody is interested…

The line comes from Ulysses (Gabler 3.1, 4: “Ineluctable modality of the visible….Limits of the diaphane. But he adds: in bodies….Diaphane, adiaphane.” See Jacques AUBERT, The Aesthetics of James Joyce, p. 134: “Color is the limit of the diaphane in any determined body.” The line comes Aristotle’s On Sense and Sensible Objects, III.439bII—specifically based on the French edition translation of “diaphane,” the edition Joyce was reading in Paris, February and March of 1903.

Stephen’s point (as far as I can determine): Stephen contrasts two fundamental ways of looking at the world, either idealist or realistic. Aristotle was a realist and had to account for the tangible impact of visible objects, e.g., the aesthetic effect of seeing a beautiful image, even though there seemed to be no physical contact between the two objects (our eye and the thing imaged). He “solved” the dilemma by comparing the transmission of visual images to that of some fluid (diaphane) flowing between the two, but a not a physical fluid; rather, Aristotle imagined some spiritual emanation that the viewer collects or grasps. Specifically, as suggested by SH Butcher—who wrote the Introduction of and translation of Aristotle’s Poetics that Joyce used in school and then later in 1904 in Italy—Aristotle held that the aesthetic effect was a real and physically transforming union of the mind of the artist and the mind of the viewer via the physical interposition of the object of art. The one who ‘knocked his sconce against it’ (Gabler 3.5—6) was Dr. Samuel Johnson, who employed that witticism to deride the Right Reverend George Berkeley’s form of idealism (that all reality is just a thought in the mind of God, and our awareness is an echo of that).

If art is viewed the idealist way, as by a Bishop Berkeley or Plato, any crafted image by any artist is simply a less-valid, less-satisfying form of the one and original Idea of whatever is imaged. Plato (and Berkeley, to a lesser extent) leave no room for that type of art that is real unto itself and has its own power…a belief that was principle and defining in the work of Dante Alighieri, whose nickname for Aristotle not only recalls The Philosopher but also echoes the word “color” (as in maestro di color che sanno,” Italian for “master of those who know”) at Gabler 3.6—7.

The Dante reference reinforces the realist bent of the opening lines, and the Sam Johnson reference (his day’s Mark Twain or Robin Williams) suggests that only a mocker, a comedian offering social commentary would challenge it (Johnson wasn’t serious in his remark and only poked fun at the man in good fun).