Daniel C. Dennett is a brilliant polemicist, famous for challenging unexamined orthodoxies. Over the last thirty years, he has played a major role in expanding our understanding of consciousness, developmental psychology, and evolutionary theory. And with such groundbreaking, critically acclaimed books as Consciousness Explained and Darwin's Dangerous Idea (a National Book Award and Pulitzer Prize finalist), he has reached a huge general and professional audience. In this new book, Dennett shows that evolution is the key to resolving the ancient problems (...) of moral and political freedom. Like the planet's atmosphere on which life depends, the conditions on which our freedom depends had to evolve, and like the atmosphere, they continue to evolve-and could be extinguished. According to Dennett, biology provides the perspective from which we can distinguish the varieties of freedom that matter. Throughout the history of life on this planet, an interacting web and internal and external conditions have provided the frameworks for the design of agents that are more free than their parts-from the unwitting gropings of the simplest life forms to the more informed activities of animals to the moral dilemmas that confront human beings living in societies. As in his previous books, Dennett weaves a richly detailed narrative enlivened by analogies as entertaining as they are challenging. Here is the story of how we came to be different from all other creatures, how our early ancestors mindlessly created human culture, and then, how culture gave us our minds, our visions, our moral problems-in a nutshell, our freedom. (shrink)

An extended examination of Libet's works led to a comprehensive reinterpretation of his results. According to this reinterpretation, the Minimum Train Duration of electrical brain stimulation should be considered as the time needed to create a brain stimulus efficient for producing conscious sensation and not as a basis for inferring the latency for conscious sensation of peripheral origin. Latency for conscious sensation with brain stimulation may occurafterthe Minimum Train Duration. Backward masking with cortical stimuli suggests a 125-300 ms minimum value (...) for the latency for conscious sensation of threshold skin stimuli. Backward enhancement is not suitable for inferring this latency. For determining temporal relations between stimuli that correspond to subjects' reports, theendof cerebral Minimum Train Duration should be used as reference, rather than its onset. Results of coupling peripheral and cortical stimuli are explained by a latency after the cortical Minimum Train Duration, having roughly the same duration as the latency for supraliminal skin stimuli. Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency. This interpretation suggests a 230 ms minimum value for the latency for conscious sensation of somatosensory near-threshold stimuli. The backward referral hypothesis, as formulated by Libet, should not be retained. Long readiness potentials preceding spontaneous conscious or nonconscious movements suggest that both kinds of movement are nonconsciously initiated. The validity of Libet's measures of W and M moments (Libet et al., 1983a) is questionable due to problems involving latencies, training, and introspective distinction of W and M. Veto of intended actions may be initially nonconscious but dependent on conscious awareness. (shrink)

Voluntary acts are preceded by electrophysiological (RPs). With spontaneous acts involving no preplanning, the main negative RP shift begins at about200 ms. Control experiments, in which a skin stimulus was timed (S), helped evaluate each subject's error in reporting the clock times for awareness of any perceived event.

In this book Daniel Wegner offers a novel understanding of the relation of consciousness, the will, and our intentional and voluntary actions. Wegner claims that our experience and common sense view according to which we can influence our behavior roughly the way we experience that we do it is an illusion.

What is the relation between a reason and an action when the reason explains the action by giving the agent's reason for doing what he did? We may call such explanations rationalizations, and say that the reason rationalizes the action. In this paper I want to defend the ancient - and common-sense - position that rationalization is a species of ordinary causal explanation. The defense no doubt requires some redeployment, but not more or less complete abandonment of the position, as (...) urged by many recent writers. (shrink)

A remarkable hypothesis has recently been advanced by Libet and promoted by Eccles which claims that there is standardly a backwards referral of conscious experiences in time, and that this constitutes empirical evidence for the failure of identity of brain states and mental states. Libet's neurophysiological data are critically examined and are found insufficient to support the hypothesis. Additionally, it is argued that even if there is a temporal displacement phenomenon to be explained, a neurophysiological explanation is most likely.