The Heart of the Mind
In this section we will comment briefly on a hornet’s nest of issues lying at the core of mental life as all of us routinely experience it, every day. These issues have been the focus of extensive recent debates, especially in the philosophical literature, precisely because of their resistance to understanding in conventional physicalist terms. The issues are deep, individually complex, and densely interconnected, and what we can say here will necessarily amount to little more than a summary of our own opinions.
Our central point is that the prevailing
a priori commitment to physicalism has rendered us systematically incapable of dealing adequately with the mind’s most central and characteristic properties.
We should rethink that commitment.
- semantic content, the "meaning" of words and other forms of representation
- intentionality - the ability of any and all representational forms to be "about" things, events, and states of affairs in the world.
"Intentionality is inherently a three-way relation involving users, symbols, and things symbolized, and the user cannot be eliminated."
homonculus
Talk of "users" and the like raises for many contemporary psychologists and philosophers the terrifying specter of the self as a homunculus, a little being within who embodies all the capacities we sought to explain in the first place. Such a result would clearly be disastrous, because that being would evidently need a similar though smaller being within itself, and so on without end. Cognitive modelers seeking to provide strictly physicalist accounts of mental functions must therefore do so without invoking a homunculus, but in attempting this they routinely fail. Often the homuncular aspect is hidden, slipped into a model by its designers or builders and covertly enlisting the semantic and intentional capacities of its users or observers.
Much contemporary work on computational modeling of memory, metaphor, and semantics harbors subtle problems of this sort. Sometimes, however, the homunculus is more brazenly evident.
One example is David Marr’s account of vision, which applies computations to the two-dimensional array of retinal input in order to generate a "description" of the three-dimensional world that provided that input, but then needs someone to interpret the description. Another is Stephen Kosslyn’s model of visual imagery, which essentially puts up an image on a sort of internal TV screen, but then needs somebody else to view the image.
Cognitive models cannot function without a homunculus, we believe, precisely because they lack what we have –
minds, with their capacities for semantics, intentionality, and all the rest built in.
No homunculus problem, however, is posed by the structure of our conscious experience itself. The efforts of Daniel Dennett and other physicalists to claim that there is such a problem, and use that to ridicule any residue of dualism, rely upon the deeply flawed metaphor of the "Cartesian theater," a place where mental contents get displayed and we pop in separately to view them. Descartes himself, James, and Searle, among others, all have this right; conscious experience comes to us whole and undivided, with the qualitative feels, phenomenological content, unity, and subjective point of view all built-in, intrinsic features.
We and our experience cannot be separated in this way.
Finally, we wish simply to record our own deepest intuition as to where these issues lead. All of the great unsolved mysteries of the mind – semantics, intentionality, volition, the self, and consciousness – seem to us inextricably interconnected, with consciousness somehow at the root of all.
The consciousness we have in mind, however, is emphatically not that of people such as David Chalmers, irreducible but ineffectual, consisting merely of phenomenological properties or "qualia" arbitrarily tacked on to some sort of computational intelligence that supposedly does all the cognitive work.
Ordinary perception, memory, and action are
saturated with conceptual understanding, and conceptual understanding is saturated with
phenomenological content.
Volition too has an intentionality aspect, for as Nietzsche somewhere remarked, one cannot just will, one must will something. And as William James so forcibly argued at the dawn of our science, all of this perceptual, cognitive, and volitional activity somehow emanates from a mysterious and elusive "spiritual self," which can often be sensed at the innermost subjective pole of our ongoing conscious experience.
We find it astonishing, and predict that it will be found so as well by our intellectual descendants, that so much of 20th-century psychology and philosophy sought – consciously! – to slight or ignore these first-person realities of the mind, and sometimes even to deny their existence. There is perhaps no better example of the power of pre-existing theoretical commitments to blind able persons to countervailing facts.
The gloomy and counterintuitive modern conclusions summarized in Section I about mind, consciousness, free will, and the self really do follow – inexorably – from the physicalism that prevails today. But as we will next briefly explain,
that kind of physicalism is itself incompatible with our deepest physical science.
