C O G I T O VOL . I NO .
Can There Be a Test for Consciousness?
HE desirability of a test for consciousness derives from its potential to resolve conï¬‚ict in several debates on interesting subjects of serious ethical importance where there is a potential to minimise suffering, such as foetal consciousness, euthanasia, animal consciousness and (perhaps soon) machine consciousness. Such a test, if formulated, might also establish the usefulness, one way or another, of debate on extra-terrestrial, plant, sub-atomic and cosmic consciousness, all of which have their ardent adherents. Finally, a test might enable us to detect consciousness where it has hitherto been ...view middle of the document...
The test must be built on the ground plan of an agreed physical deï¬nition. But researchers are fundamentally split on the issue of the deï¬nition of consciousness. One school of thought, which includes Daniel Dennett2 , Patricia Smith
L. A. Suchman, Plans and Situated Actions (Cambridge 1987) 8. D. C. Dennett, Consciousness Explained (London: Penguin 1993) 459. â€œI do resist the demand for a single, formal, properly quantiï¬ed proposition expressing the punch line of my theory. Filling in the formula (x)(x is a conscious experience if and only if . . .) and defending it against proposed counterexamples is not a good method for developing a theory of consciousness.â€
Churchland3 , Francis Crick and Christof Koch4 , Lawrence Weiskrantz5 , Heinz Pagels6 and William Lycan7 , is wary of premature deï¬nition and prefers to continue research in the belief that better understanding of consciousness will bring a clearer deï¬nition with it. This view is relevant to our question, because it strongly asserts the correlation of consciousness with physical events, but is not helpful, because it speciï¬cally declines to offer any such events as candidates. There are just as many others, for example, Bernard Baars8 , Eduardo Bisiach9 , Anthony Marcel10 , James Thompson11 and David Woods12 , who are prepared to offer their deï¬nitions of consciousness.13 The difï¬culty in this attempt is two-fold: identifying the physical events, and ï¬nding a common meaning. In none of the deï¬nitions of consciousness offered by these writers are observable physical events mentioned. Though these deï¬nitions differ in the detail, they have common failings when it comes to the question of a test. Because of this, it is possible to look at one of the deï¬nitions and draw conclusions about them all. Of the deï¬nitions, Bisiachâ€™s seems inclusive enough to represent the others as a class, yet is sufï¬ciently well constructed to illustrate the central problems of consciousness. Before looking at Bisiachâ€™s deï¬nition, I will point out that we have already encountered two major obstacles to devising an agreed test of consciousness: many writers do not even think we are able to deï¬ne what it is we seek, and those that do, do not provide any testable criteria, and differ in the detail of their deï¬nition. Bisiachâ€™s position on the question of premature deï¬nition is objective:
P. S. Churchland, â€œReduction and the Neurological Basis of Consciousnessâ€ in Consciousness in Contemporary Science ed. A. J. Marcel and E. Bisiach (Oxford 1988) 273â€“304. â€œThere is a fatal temptation to try to deal with the problem of the vagueness of â€˜consciousnessâ€™ . . . by giving stipulative deï¬nitions. . . . The difï¬culty is that, if we are not clear about the phenomena that are meant to be captured under â€˜consciousnessâ€™, stipulative deï¬nitions will not help signiï¬cantly.â€ 4 F. Crick and C. Koch, â€œThe Problem of...