Skip to main content

Better Than One: Why We Each Have Two Minds

I am posting this on behalf of David Uings, who received an MPhil for research into linguistic miscommunication, and went on to investigate the implications of split-brain research and the two visual pathways in the human brain for the philosophy of mind. His MLitt thesis was entitled Consciousness and Vision in Man: where philosophy has gone wrong. In this post David is presenting his forthcoming book, Better Than One (Karnac 2014).
Better Than One
by David Uing

We have known for more than half a century that if the link between the two halves of the human brain is severed, the separate halves reveal all the components of mindedness: perceptions, beliefs, desires, memories, thoughts and will. There are significant differences between the two minds of split-brain patients. The left mind uses language to report its perceptions, the right mind cannot. The right mind is good at visual tasks such as pattern matching at which the left mind is very poor. When the right mind acts on a perception unavailable to the left mind, that mind confabulates the reasons.

These differences provide a basis for assessing behaviour initiated by the intact brain. If someone confabulates about their reasons for action, then that action must have originated in the right mind. Wilson & Nisbett report an experiment in which subjects chose from a selection of five identical stockings. The subjects confabulated the reasons for their specific choice, indicating that it was made by the right mind (probably because there was no logical basis for a choice by the left mind).

If someone cannot report what they perceived or why they acted as they did, then that perception and action must be the responsibility of the right mind. A driver on automatic pilot has their left mind absorbed by problems at work and cannot remember or report their driving experience during this period. Never­theless, it transpires that they had obeyed several sets of traffic lights. It requires a mind to recognise that a red traffic light means stop and to initiate that action, and this can only have been the right mind.

A man gets out of bed, gets dressed, picks up two letters, leaves the house, checks for traffic before crossing the road, walks to a post box and posts the letters. He returns home and goes back to bed. When he wakes up he has no memory of what he did – he was sleepwalking. But his actions – especially checking for traffic before crossing the road – are indicative of a mind at work, which can only have been the right mind.

This is some of the evidence for the presence of two minds in the human brain; but both this and the split-brain evidence have been largely ignored by both philosophers and psychologists. I explore the reasons for this dismissal of the evidence. I explore how duality of mind can be reconciled with unity of person. I contrast the claim of two minds with the Dual System Theory (which claims two systems in the human mind, one shared with animals and one uniquely human) and with three recent books about the roles of the two hemispheres in the human brain.

I end the book with thoughts about issues that require further thought. How can Freud’s id, ego and superego be reconciled with two minds? Do we have two minds at birth, or does the left mind develop during childhood? What are the legal implications of actions being initiated by the right mind, which cannot use language to explain itself?

Popular posts from this blog

Delusions in the DSM 5

This post is by Lisa Bortolotti. How has the definition of delusions changed in the DSM 5? Here are some first impressions. In the DSM-IV (Glossary) delusions were defined as follows: Delusion. A false belief based on incorrect inference about external reality that is firmly sustained despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person's culture or subculture (e.g., it is not an article of religious faith). When a false belief involves a value judgment, it is regarded as a delusion only when the judgment is so extreme as to defy credibility.

Rationalization: Why your intelligence, vigilance and expertise probably don't protect you

Today's post is by Jonathan Ellis , Associate Professor of Philosophy and Director of the Center for Public Philosophy at the University of California, Santa Cruz, and Eric Schwitzgebel , Professor of Philosophy at the University of California, Riverside. This is the first in a two-part contribution on their paper "Rationalization in Moral and Philosophical thought" in Moral Inferences , eds. J. F. Bonnefon and B. Trémolière (Psychology Press, 2017). We’ve all been there. You’re arguing with someone – about politics, or a policy at work, or about whose turn it is to do the dishes – and they keep finding all kinds of self-serving justifications for their view. When one of their arguments is defeated, rather than rethinking their position they just leap to another argument, then maybe another. They’re rationalizing –coming up with convenient defenses for what they want to believe, rather than responding even-handedly to the points you're making. Yo

A co-citation analysis of cross-disciplinarity in the empirically-informed philosophy of mind

Today's post is by  Karen Yan (National Yang Ming Chiao Tung University) on her recent paper (co-authored with Chuan-Ya Liao), " A co-citation analysis of cross-disciplinarity in the empirically-informed philosophy of mind " ( Synthese 2023). Karen Yan What drives us to write this paper is our curiosity about what it means when philosophers of mind claim their works are informed by empirical evidence and how to assess this quality of empirically-informedness. Building on Knobe’s (2015) quantitative metaphilosophical analyses of empirically-informed philosophy of mind (EIPM), we investigated further how empirically-informed philosophers rely on empirical research and what metaphilosophical lessons to draw from our empirical results.  We utilize scientometric tools and categorization analysis to provide an empirically reliable description of EIPM. Our methodological novelty lies in integrating the co-citation analysis tool with the conceptual resources from the philosoph