tional and arousal states, and by alterations of motor activity. The apparent flow of external and internal events may be emphasized or suppressed and coupled or decoupled to a greater or lesser degree, but it is never fully suppressed in conscious states. The parallel comments 7 of Augustine and James about knowing what time is and what consciousness is, but not being able to express their nature in words, are both likely to be rooted in this curious coupling and decoupling of the flow and sampling of inner and outer states (figure 14.2). It is not surprising that the eventual development of an adequate scientific description of time in relativistic terms required conventions of measurement and an extraordinary set of rational constructions. 8
The summary remarks in this chapter may serve to show the major connections between evolution, development, morphology, and consciousness in a physical and social world. I have tried to provide the outlines of a biological theory of consciousness. My aim has been to show how the properties of consciousness can be linked to the structure and physiology of the brain and thus to offer a reasonable picture of how those properties may have evolved. Furthermore, I have attempted to suggest how consciousness might control behavior and thus contribute to survival value and fitness.
Many of the properties of consciousness can be derived more or less directly from the properties of the processes and structures from which they stem. Given the extended theory, we can account for the subjective nature of consciousness and for its relation to volition. We can also account for the observation that consciousness is neither a simple copy of experience nor a direct transfer from memorial states. In the case of linguistically competent animals such as ourselves, the theory can account for direct awareness, the extension and richness of conceptual categorization, and the ability to free the construction of plans from the bondage of present time while continuing to behave in an adaptive manner. Of course, as in every theory, there are many unexplored areas and incompletely developed ideas. But I hope I have shown that it is at least feasible to construct a self-consistent brain-based theory of consciousness without making any assumptions in addition to those already implicit in the TNGS.