One of the virtues of Fred Dretske's recent work has been the salutary openness with which he has described the motivations he discovers controlling his thought, and this candor has brought a submerged confusion close to the surface. Since this confusion is widely shared by philosophers and others working on the problem of content ascription, an analysis of its influence on Dretske will at the same time illuminate the difficulties it is creating for other writers.
I think the confusion is born of the misalliance of two background images we have, each of which is valuable in itself but liable to be subscribed to in exaggerated form.Endnote 2
First, there is the image of mining the past for the future. The purpose of brains is to "produce future", as the poet Valéry said: to create anticipations and expectations that will guide an organism's actions along the paths that avoid harm and capture good.Endnote 3 The raw materials for the production of reliable anticipations must come in via our sense organs, to be stored in our memories. The plasticity of our brains permits us to learn. As this image would have it, learning is a matter of extracting meaning from our interactions for use in the future. There is really no doubt that this is what our nervous systems are for, but how exactly this process of information-extraction and subsequent meaning-manufacture is accomplished remains a mystery. How, we ask, can we get the fruits of our transactions with the past to inform and guide our future acts? "Theories of meaning" or "theories of content ascription" or "psychosemantics" are all attempts either to answer this question or at least to erect and justify families of constraints on acceptable answers.
Second, there is the image of what it feels like to come to understand something: there you are, encountering something somewhat perplexing or indecipherable or at least as yet unknown--something that in one way or another creates the epistemic itch, when finally Aha! I've got it! Understanding dawns, and the item is transformed; it becomes useful, comprehended, within your control. Before time t the thing was not understood; after time t, it was understood--a clearly marked state transition that can often be accurately timed, even though it is, emphatically, a subjectively accessible, introspectively discovered transition.
(The whole paper is now available in Daniel Dennett, Brainchildren, Essays on Designing Minds, MIT Press and Penguin, 1998.)
1.This paper incorporates portions of an earlier paper, "Ways of Establishing Harmony," in E. Villanueva, ed., 1990, Information, Semantics & Epistemology, Oxford; Blackwell, and forthcoming in B. McLaughlin, ed., [volume on Dretske], Oxford; Blackwell.
2.This confusion was suggested to me by Kathleen Akins, in "On Piranhas, Narcissism and Mental Representation," Univ. of Michigan Phd dissertation, 1988, where she draws a similar distinction, but uses the distinction for quite different philosophical purposes."
3. See the discussion of the verbs of "making a difference", such as "avoid", "prevent", "foster" etc., in my Elbow Room, 1984. See also my "Producing Future by Telling Stories," forthcoming in Kenneth M. Ford and Zenon Pylyshyn, eds., The Robot's Dilemma Revisited: the Frame Problem in Artificial Intelligence, Ablex.