Natika Newton

Nicholas Maxwell takes on the ambitious project of explaining, both epistemologically and metaphysically, the physical universe and human existence within it. His vision is appealing; he unites the physical and the personal by means of the concepts of aim and value, which he sees as the keys to explaining traditional physical puzzles. Given the current popularity of theories of goal-oriented dynamical systems in biology and cognitive science, this approach is timely. But a large vision requires firm and nuanced arguments to support it. Here Maxwell's work is weakest; his arguments for contingent mind-body identity and for free will, on which his larger theory depends, are inadequate. The book is valuable both for its comprehensive view of the human condition and its mysteries, and for its demonstration of the difficulties in making such a view coherent.

John Searle has argued that one can imagine embodying a machine running any computer program without understanding the symbols, and hence that purely computational processes do not yield understanding. The disagreement this argument has generated stems, I hold, from ambiguity in talk of 'understanding'. The concept is analysed as a relation between subjects and symbols having two components: a formal and an intentional. The central question, then becomes whether a machine could possess the intentional component with or without the formal component. I argue that the intentional state of a symbol's being meaningful to a subject is a functionally definable relation between the symbol and certain past and present states of the subject, and that a machine could bear this relation to a symbol. I sketch a machine which could be said to possess, in primitive form, the intentional component of understanding. Even if the machine, in lacking consciousness, lacks full understanding, it contributes to a theory of understanding and constitutes a counterexample to the Chinese Room argument.

The notion of introspection is unparsimonious and unnecessary to explain the experiential grounding of our mentalistic concepts. Instead, we can look at subtle proprioceptive experiences, such as the experience of agency in planning motor acts, which may be explained in part by the phenomenon of collateral discharge or efference copy. Proprioceptive sensations experienced during perceptual and motor activity may account for everything that has traditionally been attributed to a special mental activity called “introspection.”.