Online research in philosophy

This paper challenges the widely held theory that split-brain patients have ‘two-minds’ and can thus be described as being two distinct persons. A distinction is made between the singularity of mind and the coherence of mind. It is stressed that ‘a single mind’ is not something posited to explain coherence among mental contents, but is merely a mark that such coherence holds to a certain degree. However, there is no sharp dividing line regarding what counts as a single mind. It is argued that mental coherence is always a matter of degree, and that our concept of a single mind can accomodate spit-brain phenomena.

Perception is sensory awareness. Cognition is reflective awareness. Consciousness is awareness-as-such. In Indian psychology, as represented by Samkhya-Yoga and Advaita Vedanta systems, consciousness and mind are fundamentally different. Reality is the composite of being (sat), knowing (cit) and feeling (ananda). Consciousness is the knowledge side of the universe. It is the ground condition of all awareness. Consciousness is not a part or aspect of the mind. Mind is physical and consciousness is not. Consciousness does not interact with the mind, the brain or any other physical objects or processes. Nor does it have any causative role in mental activity. Hence the existence of consciousness does not interfere or upset the apparently closed physical system. Mind in this view is the interfacing instrumentality that faces consciousness on one side and the brain and the rest of the physical world on the other. Mind is closely connected with the different systems of the brain. In normal perceptions, the mind takes the forms of objects via the channels of the sensory system and the processes in the brain. The forms themselves are non-conscious representations of the world of objects. The mental forms (vrittis) become conscious experiences in the light of the purusha. The vritti in sensory form is perception and with the reflection of the purusha it becomes cognition. All conscious perceptions are therefore cognitions.

In this book, Hodgson presents a clear and compelling case against today's orthodox mechanistic view of the brain-mind, and in favor of the view that "the mind matters." In the course of the argument he ranges over such topics as consciousness, informal reasoning, computers, evolution, and quantum indeterminancy and non-locality. Although written from a philosophical viewpoint, the book has important implications for the sciences concerned with the brain-mind problem. At the same time, it is largely non-technical, and thus accessible to the non-specialist reader.

According to conventional wisdom, the split-brain syndrome puts paid to the thesis that consciousness is necessarily unified. The aim of this paper is to challenge that view. I argue both that disunity models of the split-brain are highly problematic, and that there is much to recommend a model of the split-brain—the switch model—according to which split-brain patients retain a fully unified consciousness at all times. Although the task of examining the unity of consciousness through the lens of the split-brain syndrome is not a new one—such projects date back to Nagel’s seminal paper on the topic—the time is ripe for a re-evaluation of the issues.

In "Consciousness Explained," Dennett (1991) denies that split-brain humans have double consciousness: he describes the experiments as "anecdotal." In attempting to replace the Cartesian Theatre of the Mind" with his own "Multiple Drafts" view of consciousness, Dennett rejects the notion of the mind as a countable thing in favour of its being a mere "abstraction." His criticisms of the standard interpretation of the split-brain data are analyzed here and each is found to be open to objections. There exist people who have survived left ["dominant"] cerebral hemispherectomy; by Dennett's criteria, they would not have minds.