The skeptic against coherence
I will introduce some new terms, and an attempt to clarify them will not be forthcoming. Perhaps they will be “high definitions” or their meaning will be unclear. Consider this a methodological dogma (rationalism).
Moore claims that (1) I know that this is a hand, thus I know I am not dreaming as contrapositive to (2) I do not know that I am not dreaming, thus I do not know this is a hand. Moore subsequently and entertainingly waves his hands. The argument is more subtle than this. The truth of (i) I know this is a hand and (ii) I know this other is a hand shows that when conjoined, (iii) I know I have hands follows. The idea is that (1) and (2) are logically equivalent and (1) is more plausible than (2).
My refutation of the skeptic centers on coherency of story. The skeptic wants us to believe all the sensible qualities of the world are consistent with dreaming. But does the skeptic claim that coherency of dreaming, or being a brain in a vat, is consistent? I know that I am not dreaming because of the semantic space in which dreams and waking take stage. In dreaming peculiar things occur. Objects may or may not bear their usual (in waking) features. A cat, for instance, my have 4 legs in my dream, but I recall that same cat in waking as having four. It is inconsistent waking, as we may suppose, that the cat have 3 legs in dreaming. This will increase our awareness, perhaps, of our dreaming. Under assumption, waking does not involve our cats having 3 legs and them sprouting a fourth. I suppose this does not involve semantic space, but it is the coherence in which semantic space must take place. It is an assumption that objects correspond to certain features. Thus, “grass is green” if and only if grass is green refers to a state of affairs. Grass becoming blue is consistent, from a metaphysical standpoint. Its atomic structure may be different so as to be conducive to us perceiving blue grass as opposed to green grass. But grass is spaghetti? Well, we might recall Descartes’ claim of “mundane events” that take place in dreams. So we must take Descartes hypothesis and ignore very peculiar situations like grass is spaghetti. But must we suppose that the arch-skeptic further supposes that the dream be “coherent in the mundane” sense? Will dreams not at first blush seem mundane in coherence (general features of consistency)? This seems agreeable. But will all features be coherent so as to have no inconsistency whatsoever? The dream-demon may strive for coherency in tricking our consciousness. But I exert my power in assuring that the dream is coherent internally. Other persons will interpret my “dreaming life” or my “waking life” incorrectly. I will exert my power to correct the inconsistency of the state of affairs. Can the dream-demon cause all agents within my dreaming or waking to present inconsistency for something about me? Someone recalls a story about me incorrectly. I correct this person. Will I have at this point adjusted the parameters of my dreaming? Do I have this kind of power insofar as our usual conception of dreaming?
I know this story as coherent, thus I know I am not dreaming.
I do not know I am not dreaming, thus I do not know this story as coherent.
But it seems I can map to the world through coherence, if not correspondence. My effort to make the world cohere eliminates a feature of dreaming: its incoherence. Are dreams always coherent? Well, Cartesian Skeptics may posit that all of our dreams can be coherent and mundane. Fine. Does the dream-demon have control over what I will see as coherent and as incoherent qua story? The stories will be layered, agent A this, agent B that story that is inconsistent with my own. I will exert my power to “align” the stories, to correct them, to make them coherent.