"Ineluctable modality of the visible: at least that if no more, thought through my eyes": at the beginning of Proteus Stephen is thinking about sight, and continuing the balancing act between prophetic vision and Aristotelian empiricism that occupied him at the beginning of Nestor. Trying a thought experiment to see if he can access ultimate reality by transcending sensory appearances, he decides that he cannot, and spends the rest of the chapter looking around him.
"Ineluctable" means simply unavoidable or inevitable, but its etymology is interesting: the Latin eluctari means to struggle out of. The word's root meaning implies, then, that Stephen is struggling to escape from the "modality of the visible." And indeed, at the end of the first paragraph he thinks, "Shut your eyes and see." He wishes that there might be an alternative to physical sight, some mode of spiritual vision that he could access by blacking out the input of the senses. Near the end of the next paragraph, walking along the sand with his eyes closed tight, he thinks, "Am I walking into eternity along Sandymount strand?"
The answer to his question will be No, but he already has the answer before conducting his bizarre experiment: he knows that physical vision is "ineluctable." Stephen's struggle to overcome sight recalls his struggle to overcome the bitter facts of history at the beginning of Nestor, where he decided that "they are not to be thought away." And it anticipates Shakespeare's struggle (in Scylla and Charybdis) to overcome the disastrous facts of his sexual life, which similarly could only be thought about, not thought away.
In the case of physical sight, the text suggests that ineluctability may not be a bad thing. The phrase that follows, "at least that if no more," implies that sight is something to start with. Like Descartes who doubted the existence of everything in his experience until he found one solid foundation on which to build his philosophy, Stephen at least has sight, "thought through my eyes," on which to center his existence.
Thornton suggests that "Ineluctable modality of the visible" may have been inspired by Aristotle's De Anima, but acknowledges that "nowhere have I found this exact phrase." Gifford too fails to find an exact Aristotelian analogue, but Stephen does think often of Aristotle in the remainder of the paragraph. Against the Greek philosopher's empiricist understanding of sight, he is soon advancing idealist understandings inspired by his reading of Jakob Boehme and George Berkeley. The thought that comes through the eyes, according to these conceptions, is not knowledge of physical objects and processes, but spiritual insight. But Aristotelian materialism seems to have the last word. When Stephen opens his eyes to find that he has not succeeded in blinking the world away, he thinks, "See now. There all the time without you: and ever shall be, world without end." The concluding phrase echoes Aristotle's understanding of matter, which Joyce associated with Proteus.
Stephen struggles to reconcile Aristotelian empiricism with his cherished models of spiritual idealism, but he always holds fast to the former as the ineluctable basis for understanding reality. In Scylla and Charybdis, thinking once more of Aristotle as a guide to understanding the prodigious reality of William Shakespeare's corpus, he resolves to "Hold to the now, the here, through which all future plunges to the past."