As before, the Pequod steeply leaned over towards the sperm whale’s head, now, by the counterpoise of both heads, she regained her even keel; though sorely strained, you may well believe. So, when on one side you hoist in Locke’s head, you go over that way; but now, on the other side, hoist in Kant’s and you come back again; but in very poor plight. Thus, some minds for ever keep trimming boat. Oh, ye foolish! Throw all these thunder-heads overboard, and then you will float light and right. – Herman Melville, Moby-Dick, Chapter 73: “Stubb and Flask kill a Right Whale; and Then Have a Talk over Him”Their talk was of the devil. Stubb, the Pequod’s second mate, called a “dog” by Captain Ahab early in the story, is convinced that one of the strange men who only appeared on board long after the ship was at sea is, in fact, the devil, the immortal devil, on board to win Ahab’s soul in return for the capture of the white whale. But it is not this talk of the devil that I want to relate to John Locke and Immanuel Kant, giants of Western philosophy, but Ishmael’s lecture to readers in the following chapter, and in particular that section of the chapter focused on whales’ eyes and the difference in their vision from our own.Moreover, while in most other animals that I can now think of the eyes are so planted as imperceptibly to blend their visual power so as to produce one picture and not two to the brain; the peculiar position of the whale’s eyes, effectually divided as they are by many cubic feet of solid head, which towers between them like a great mountain separating two lakes in valleys; this, of course, must wholly separate the impressions which each independent organ imparts.Skipping the rest of that paragraph and Melville’s analogy to sash windows (I am more taken by the picturesque two valley lakes separated by the mountains, although the windows speak more directly to seeing), we come to this:A curious and puzzling question might be started concerning this visual matter as touching the Leviathan. But I must be content with a hint. So long as a man’s eyes are open in the light, the act of seeing is involuntary; that is, he cannot then help mechanically seeing whatever objects are before him. Nevertheless, any one’s experience will teach him, that though he can take in an undiscriminating sweep of things at one glance, it is quite impossible for him, attentively, and completely, to examine any two things—however large or however small—at one and the same instant of time; never mind if they lie side by side and touch each other.We human beings, Melville is pointing out, can only look at two things by looking first at one and then at the other, back and forth. This brings to my mind a very strange discovery I made in the fourth decade of my life. I had gone to a new eye doctor for an exam, and he made some casual, passing remark about my “crooked eye.” I was in a state of shock for days. Crooked eye? What crooked eye? It was true I’d noticed something odd in snapshots but dismissed the oddity by accepting that I was not photogenic. When a neighbor made a pencil drawing of me—I was in my early teens at the time—and my eyes in the portrait did not quite match up, all I could think was that she was “not a very good artist.” Now here was a physician telling me—but not telling me, because he assumed I’d always known—that I had a crooked eye! You may imagine how closely I examined my face in the mirror. And that was when I realized for the first time the limitations of binocular vision: I could only look into one of my eyes at a time, not both at once.“Did you know I had a crooked eye?” I asked my mother. “Oh, yes, we knew,” she replied. “But”—still incredulous—“you never mentioned it!” “We didn’t want you to be self-conscious.” Well! Well, all right! That was long ago now, and I’m over it (except for noticing, with benevolent fellow feeling, crooked eyes in others I meet or see in movies or whatever), but try it yourself if you are skeptical. And now, back to Melville--.How is it, then, with the whale? True, both his eyes, in themselves, must simultaneously act; but is his brain so much more comprehensive, combining, and subtle than man’s, that he can at the same moment of time attentively examine two distinct prospects, one on one side of him, and the other in an exactly opposite direction? If he can, then is it [Melville is saying that it is, not asking a question] as marvellous a thing in him, as if a man were able simultaneously to go through the demonstrations of two distinct problems in Euclid. Nor, strictly investigated, is there any incongruity in this comparison.Well, now what about that business of listing between the empiricism of Locke and the idealism of Kant? If we had whale vision and whale brains, would we have to choose between Locke and Kant, or could we examine both simultaneously and be convinced by both in the same moment? Would we have to choose between Plato and Aristotle or Paris and Venice or even Democratic and Republican, or could we hold all oppositions of belief and view and preference at once?It is often pointed out that human beings do believe contradictions in many areas of life. We say we want to achieve a certain goal, and yet we speed nonstop in the opposite direction. All too often, our mouths speak one set of values, and our lives demonstrate another. Are we so different from our mammal relatives in the sea, after all? Or is the human being, each individual’s thought, divided against itself, “very like a whale”?