Commissurotomy, Consciousness, and Unity of Mind
The author writes:
"Recent pyschological studies of commissurotomy patients have provoked considerable, sometimes wild, speculation by both philosophers and the experimenters themselves. Among neuropsychologists, the prevalent view is that the split-brain patient has two minds. These two minds are taken to exemplify a variety of dichotomies: for example, one is atomistic, analytical, digital, symbolic, discursive; the other, holistic, synthetic, analogic, perceptual, eidetic. Further, it is inferred, there is a similar split in the fundamental cogntive styles of the left and right halves of the intact brain, whether or not they are also counted as separate minds. . . . In this monograph, my primary concern is the number of minds split-brain patients have; the speculations on what types of minds these may be . . .are left for another time. I advocate a conservative assessment of split-brain research: the split-brain patient has one mind and is one person, although he has on occasion a disunified consciousness."
"Marks's exploration of some of the philosophical implications of the split-brain syndrome is a model of work in philosophy of psychology. It is carefully reasoned, yet not esoteric; empirically sophisticated, yet to the point; teachable, while at the same time an important contribution to the field. This monograph should be of interest to anyone concerned with the relationship of mind to brain—students, professional philosophers, psychologists, and neuroscientists alike."
—Barbara Von Eckhardt Klein, Yale University
"This is a superb monograph. It raises the debate on the philosophical issues connected with split-brain research to a much higher level than before.
"That the split brain case is philosophically perplexing is undeniable; a description of the experiments of Sperry and others strikes not only philosophers but philosophy students and laymen as raising significant issues about what it is to have a single mind. The split brain cases have come to play a role in philosophy classes like that of other cases which are about equally puzzling but wholly fictional. Marks' piece is a major advance...It would be a terrific choice for a course on the philosophy of psychology or for a seminar in philosophy or psychology."
—John R. Perry, Stanford University