No, it involves many, at least many.
Again, I ask that what you say be tested. What we doubt, what descartes does is really only doubting one thing.
Yeah, I admit enjoying stating the obvious. Every once in awhile, you get someone who says, “I never saw it like that before”. We do have a culture, civilization that, to some extent, avoids the obvious in search of the secret.
I don’t understand your reply. You did not state the obvious. I disagreed with you. I pointed out that although (here is another example) we do not say, “Please pass the NCl” when we say, “Please pass the salt,” that is, in fact, what we are saying. Do you agree?
Huh? You disagreed with me? Well, okay. I guess I misunderstood that ‘of course’. It does nothing to salt to describe it as salt or as NACL. The appropriateness of any description depends on ‘our’ goals, not on the essence of salt.
I thought about going after ‘wise’ but changed my mind. I guess I should have. There is no outside point of view, no skyhook, no way to have a view from nowhere. The wise are not more in touch with reality, we are all in touch with reality. We just describe it differently.
It occurs to me that Plato’s Allegory of the Cave might illuminate the issue. Take the position of the prisoners facing the inner wall of the cave and watching only the shadows of the real objects passing outside of the cave. So far as they are concerned, the shadows are the reality. Now, that there are real objects outside the cave is true, but the prisoners don’t know of them. Some great metaphysician among them might speculate that perhaps what they see is not real, and that there is a reality somewhere, but that does not mean he believes in the existence of that reality. He has only the concept of such a thing, and perhaps he dismisses it as a fantasy. What he believes is that the shadows are real.
So the question is, what must that metaphysician believe is true to doubt that the shadows are real? Nothing, that I can see which is germane to the issue.
I do disagree, and I think I understand you.
Why is the scientific image superior to the manifest image, to use Sellars’ language?
Because we can explain the manifest image in terms of the scientific image, but not vice versa. For instance, we can explain why (and how) the manifest image is the manifest image: Why a world of electrons and other microparticles whizzing around at enormous velocities appear as middle-sized objects to us. But we cannot give an explanation the other way round. To put it a bit differently, we can understand the manifest image in terms of the scientific image, but not vice versa. And, of course, we can do other things with the scientific image that we cannot do with the manifest image. For instance, we can get (or at least try to get) a picture of the whole, how, for instance, electricity works with (maybe) gravity.
I don’t think that the scientific image is a “skyhook” in anything like the sense Davidson means that. The scientific image integrates the manifest image and connects with it. It is a picture of the world from within, but a superior one.
But this is just confusing speculation with doubt. If he believes the shadows are real, he doesn’t doubt them. I’m certainly not trying to make a case against speculation – that would turn my points away from the sceptic and toward fiction. I certainly don’t want to deny that fiction exists.
Gotta go, wife says she’s hungry. 
Let me try to expand on that. What Descartes says is that if it is possible to doubt something, it must be rejected as a foundation for certainty. What I say following Davidson is that it is not possible to doubt something without at the first time believing in many other things.
Plato, or rather the great metaphysician, doesn’t really doubt that the shadows are real, what he thinks is that there is another world, presumably the world that casts those shadows on the cave wall (which he doesn’t doubt, nor does he doubt the imprisonment of those other, less gifted, metaphysicians) that is somehow realler than the real shadows. That is, that we’re not getting the whole picture. The doubt therefore is really only one doubt, doubting whether what we see are shadows of another world, but those shadows, in order for them to be shadows, must be just as real as, well, the real world.
In other words, I think Plato and Descartes are really talking about two different things. It’s certainly okay to speculate, it’s fun too, but if we’re going to take those things seriously, as a useful description of the world, we have to examine the nature of doubt and this is not something Descartes does.
I think.
Whereas you use Plato’s cave as an example, I think he set the terms of the debates as Descartes did at a later stage. They didn’t recognize the problem so much as create the parameters for the problem in the first place. I see no reason to accept scientific description as superior in all cases, or as you put it
But why is it superior? Is it superior because it is a more accurate description? I do not see how we can compare descriptions in this way unless we posit the very thing we’re trying to describe, that we already know the thing we’re trying to measure and can test it against what we already know is the real world. That is, of course, exactly what we do, but it’s not between the world and our description, it’s between two different descriptions.
Rather than deal with these problems why do we have to posit a privileged description for everything at all (We do, I think, because we still follow Plato in some sense)? Why not see these descriptions as useful for certain purposes and not for others, or why not even see them as different languages?
If looked at this way,
is like saying that we can translate from Chinese into English but not vice versa. As I write that, I immediately think of the notorious difficulties of translating Joyce’s ‘Ulysses’ into Chinese. So, yes, some languages are more useful than others for certain purposes, but I don’t see how that makes translation impossible.
Just difficult.
And besides, I think many scientists have made great efforts to explain science in manifest images so that those who do not speak their language can understand what they are doing (Are popular science books really a fool’s errand?).
I’m confused here (that should be obvious by now). You say we can’t explain how electrons and micro-particles whizzing around at enormous velocities with middle-sized objects. But isn’t that what you just did? Whizzing, velocities, particles (and waves, strings, slingshots, bubbles, etc) are all references to middle-sized objects. Newton didn’t invent the world ‘gravity’, he used gravitas as a metaphor.
It’s interesting that you would use physics as your example here. That was, no doubt, the paradigm field of the twentieth century, but many have pointed to a shift in thinking here, to a biological paradigm in the twenty-first and sure enough we have theories that explain physics (why the universe is the way it is) in terms of evolution.
Now with all that said, I don’t want to be misunderstood as being anti-science. I’m not, but I can’t help but wonder if by placing it on a metaphysical pedestal, we don’t inadvertantly set it up for a fall. Scientific description’s greatest strength is its ability to change based on results (as opposed to sheer force), but that makes it a very difficult standard bearer of certainty.