(A few months ago I contributed this to a panel on Existentialism and Phenomenology at The Gnus Room, here in Auburn. I had fewer than ten minutes and was addressing a group of students and townsfolk.)
Philosophy moves in mysterious ways. It perhaps moves most mysteriously in phenomenology. Typically, when we reflect on philosophy, what stands out is the peculiar conflict between what philosophy tells us and what common sense tells us, and the feeling of discovery that accompanies that conflict. We take ourselves, for example, to see stuff: other people, chairs, cars, rainbows, flames, stars and mirror images. But the philosopher tells us that, as a matter of strict visual fact, what we see is not that stuff, but other stuff: sense-data. Think of sense-data as infinitely thin ethereal photographs that appear and disappear before the mind’s eye. When I see a chair, what I really see is a sense-datum of the chair, an infinitely thin ethereal photograph of the chair. (Who took it? God knows. Maybe He took it.) That sense-datum is what my actual seeing of a chair and my hallucinatory seeing of a chair have in common. And in fact, it is the hallucinatory seeing of chairs that seem to require sense-data. The actual seeing of a chair and the hallucinatory seeing of a chair are, after all, hard to tell apart, otherwise we would scarcely be taken in by our hallucinatory seeing. –So the thought goes; and so we decide that there must in fact be something that the two do have in common: Lo! Sense-data. The philosopher thus tells us something that conflicts with common sense and that feels like a discovery. We do not see chairs, ever, really; we see chair-ish sense data.
I said that you could think of sense-data as infinitely thin ethereal photographs. A photograph, as you know, always presents its subject perspectivally. If I photograph a chair, I do so from a particular angle, perhaps a little above it and standing just off to the side of it. The photograph then forever presents the chair from just that perspective. Of course, I can change my perspective on the photograph of the chair itself, but that does not change the perspective of the photograph on the chair. That is settled, fixed, forever. Ditto, almost, for the sense-datum of a chair. It, too, presents the chair from a particular perspective. But I cannot change my perspective on the sense-datum. In fact, I have no perspective, really, on the sense-datum. It represents the chair from some visual angle or other, but I have no angle on the sense-datum. The sense-datum is, after all, at no visual distance from me. It is not only infinitely thin; it is infinitely intimate, closer to me than I am to myself. I cannot wave my hand between the sense-datum and myself. All that happens in such a case is I replace my intimate sense-datum of a chair with an equally intimate sense-datum of a hand in front of a chair. There is no visual space between that sense-datum and me. I cannot move so as to see a sense-datum better; if I move, I simply change sense-data.
What has happened is that the sort of thing I took myself to be able to see, a chair, has been replaced by sense-datum of a chair. The chair I took to transcend my consciousness of it—by which I mean that I took there to be more to my visual object, the chair, than met my eye at any given moment. But it turns out that my actual visual object, the sense-datum of the chair, is exhausted in my vision of it. Let’s call its being exhausted its being immanent to my consciousness of it. Actual chairs have visual secrets, a kind of visual modesty—paint smears, or scratches or stuck-on wads of gum that cannot be seen from my current perspective on the chair. But sense-data have no visual secrets, no visual modesty at all. They are all display.
I have been trying to get you into the spirit of what is sometimes called phenomenalism. Phenomenalism easily gets confused with phenomenology. But they are quite different. I can give you a sense of what phenomenology is by doing a bit of it so as to show its contrast with phenomenalism.
For phenomenology, perception is perspectival: but that is as much to characterize the objects of perception, as it is to characterize perceptions. Chairs, to revert to our comfortable example, are perspectival. What does that mean? Well, it means that they are such as to have visual secrets, to be visually modest, to come to us as “inexhaustibly rich”; it means that they are things. My seeing a chair perspectivally is not a subjective distortion of an ideal objective experience of seeing all-of-the-chair all-at-once. The chair is not displaying all of itself all-at-once; it is not all display. To take it as if it were is to treat the chair as if it could all be seen all-at-once. But that it true of sense-data; it is not true of chairs. Rather, my seeing the chair perspectivally assures me that I am communing with a real world, one richer than I currently know or could ever know, one in which there are discoveries to be made—with my eyes and not with the eye of the mind. But to rightly understand this, we must bear in mind that my perspectival seeing does not interpose itself between the chair and me—as if the chair seen in perspective was itself more like a door than a window—but is instead the chair manifesting itself to my eyes. My perspectival seeing of a chair is a seeing of the chair. The perspectival seeing of the chair is not related to the chair in-itself as a herald is to the coming king, or as a sign is to a city about to be entered. My perspectival seeing of the chair introduces me to its bodily reality. True, the chair transcends my seeing of it, it is not immanent to my consciousness, but its very transcendence is open to my knowledge, to further visual investigation, for example. Its transcendence does not supply content to my ignorance, as it were. It instead beckons my knowing, my seeing, farther along. Its transcendence awaits my knowing, my seeing, like the young girls awaiting the wedding of the Bridegroom.
I know that is a lot to take in. But notice this about it: my little bit of phenomenology, although it may strike you as odd or as otherwise unusual, should not strike you as itself conflicting with common sense nor as providing a feeling of discovery. If you followed it, what you should have had a sense of was not conflict and discovery, but rather of the efflorescence of the familiar. In other words, if my little bit of phenomenology is at all successful, it should make you feel that seeing has bloomed, that both your sight and the objects of your sight have stepped forward, so that you know them again as if for the first time. Think of it as like a second First Kiss.
Phenomenology declares itself descriptive, not explanatory. I take that to mean that when it is successful, what it tells us does seem to conflict with common sense and does not seem as if it involved a discovery. Instead, it gives us new knowledge of what we already know; it deepens our acquaintance with and tightens our ties to things. Phenomenology is philosophy—but not philosophy as we typically think of it.
 But not before your eyes, blue or brown or green. Our eyes may be involved in the story of the sort of sense-datum that appears before the mind’s eye (it has only one, cyclopic), they may be involved in the sense-datum being classified as visual; but the sense-datum is not something we see with our eyes.