Susan L. Hurley
Consciousness in Action
Cambridge, MA: Harvard University Press, 1998,
xii + 506 pp., $55.00, ISBN 0-674-16420-2 (hbk).
Published in: Journal of Consciousness Studies, 7, 5, pp. 83-84 (May 2000).
© Josh Weisberg
In this fascinating book, Susan L. Hurley defends the thesis that action and perception are deeply and fundamentally intertwined, contrary to traditional assumptions in the philosophy of mind and cognitive science. Hurley calls her position the Two-Level Interdependence View. She contrasts it to the input-output picture, which sees perception and intentional action as essentially disconnected. This creates the “classical sandwich” view of mind on which perception and action flank cognition like protective buffers, separating thought from the world. Despite recent work that calls this picture into question (i.e., the literature on embodiment and dynamic systems), it is still widely shared by supporters of otherwise disparate views of content, action, and consciousness.
Hurley develops and defends her thesis in ten interconnected essays grouped into two main sections. In part I, she argues that the Two-Level Interdependence View can explain how separate conscious states are unified in consciousness without falling into the conflations and errors which plague other accounts. In part II Hurley focuses on the relationship between perception and action, with an eye toward debunking the received input-output picture. She considers a variety of issues in philosophy, cognitive psychology, neuroscience, and action theory which highlight the deep interconnection between experience and intention.
Part I of the book addresses the unity of consciousness. My co-occurent conscious states all seem to fit together in an undivided subjective experience. What makes co-conscious states members of one unified center of consciousness? Hurley argues that both personal-level and subpersonal-level considerations must be employed in any account of unity. In addition, seeing the content of perception and action as intertwined helps explain the important perspectival elements of unified consciousness.
Hurley considers whether normative constraints on personal-level content alone can provide grounds for unity. She argues that they are necessary but not sufficient, given the possibility of duplicate but consistent contents in separate centers of consciousness. To provide the needed subpersonal complement to norms of content, Hurley introduces the idea of a dynamic singularity. She defines a dynamic singularity as “a continuous and complex dynamic system centered on an active organism, with feedback loops that may have external as well as internal orbits” (333). The dynamic nature of this system allows for a complex connection between perception and action at the personal level, while providing a criteria for individuating centers of consciousness at the subpersonal level.
The presence of a perspective is also required for the unity of consciousness. Hurley claims that “having a perspective involves keeping track . . . of the ways in which what you experience and perceive depends on what you do” (140). This capacity can be traced back to the codependence of perception and action on the same dynamic singularity. Thus unity is explained by invoking interconnected personal-level contents, which are instantiated by an environmentally embedded dynamic system. The contents of perception and action are further unified by conforming to norms of consistency and rationality.
In Part II of the book, Hurley looks at the relationship between perception and action from a number of different angles. She brings out how the input-output picture is assumed in various thought experiments in philosophy, which take for granted that an organism’s internal states can be duplicated across various environments. By introducing complications involving visual and proprioceptive feedback, Hurley demonstrates that the sharp line between inner and outer states required by the traditional picture cannot be drawn. She concludes that the more flexible Two-Level View is better suited to handle the intricacies of the interaction between experience and intention.
Hurley also examines an assortment of results from neuroscience and psychology which call the input-output picture into question. She focuses in particular on examples where input is held fixed, but perceptual experience changes. For instance, Hurley discusses cases where subjects with paralyzed eye muscles experience a “jump” in what they see when they try and fail to move their paralyzed eye. Though the input to the eye is constant, the content of perception shifts. Hurley argues that the initiating of intentional action triggers the shift. This interpretation demands a deeper link between perception and action than the input-output picture allows. If intention to act is reaching back to influence what is experienced, perception and action cannot be so disconnected.
Hurley thus concludes that the Two-Level Interdependence View can provide a framework for an account of unity, while respecting the complexity of the relations between experience and intention. We are presented with a picture of the mind as dynamically embedded in the environment, unified by the interconnections between perceptual and intentional content. Perception and action are seen as horizontally rather than vertically modular, like twisted strands of rope stretching from the world through the mind, instead of like encapsulated blocks in a line. We are woven into the world instead of being set back at a distance.
I find Hurley’s main points concerning the interdependence of perception and action to be compelling, and I believe her Two-Level View represents an important and original shift in thinking about the mind’s place in the world. I will close, however, with a concern about the route that Hurley has taken to reach her results, as well as a question about the relation of her thesis to the issue of what makes a mental state conscious.
Hurley motivates her position by addressing the unity of consciousness. But work by Daniel Dennett (1991), and Anthony Marcel (1993) suggests that though consciousness seems unified, our experience may actually be disunified. We may be designed not to notice the disunity, or even to misrepresent it as unified. Unity may be only an apparent feature of experience. This potentially dissolves the problem of unity, dissipating some of the support for the Two-Level View offered by Part I of the Book.
In addition, Hurley has admittedly little to say about what makes mental states conscious in the first place. But if there is no pressing problem of unity, Hurley is faced with the challenge of explicating the explanatory link between action and consciousness. The complexity of the relationship between the content of perception and action is well argued for throughout the book. But interdependent content can also occur unconsciously. So the issue of consciousness may be somewhat separate from the action-based considerations that Hurley skillfully presents.
However these questions turn out, Hurley has presented a wealth of enlightening information concerning action, perception, and mind. She has crafted a rich and impressive book that is required reading by researchers in philosophy and cognitive science. Action and Consciousness is a major contribution to the field.
Josh Weisberg CUNY Graduate Center
REFERENCES
Dennett, Daniel C. (1991). Consciousness Explained. Boston: Little, Brown.
Marcel, Anthony J. (1993). “Slippage in the Unity of Consciousness.” In Experimental and Theoretical Studies of Consciousness, G. Bock and J. Marsh, eds. Chichester, England: John Wiley & Sons, 168-179.