Tim Bayne is a philosopher of mind and cognitive science, with a particular interest in the nature of consciousness. He is currently Professor of Philosophy at Monash University (Melbourne), having taught previously at Macquarie University, the University of Western Ontario, the University of Manchester and the University of Oxford. He is the author of The Unity of Consciousness (2010), Thought: A Very Short Introduction (2013), and most recently Philosophy of Mind (2021). He is an editor of Delusion and Self-Deception (2008), The Oxford Companion to Consciousness (2009) and Cognitive Phenomenology (2011). His current research concerns the measurement of consciousness, and whether it is possible to build a consciousness meter. Other research interests include the nature of conscious thought, disorders of consciousness and taxonomy in psychiatry.
We have various everyday measures for identifying the presence of consciousness, such as the capacity for verbal report and the intentional control of behaviour. However, there are many contexts in which these measures are difficult (if not impossible) to apply, or in which these measures can be applied but we have serious doubts as to their validity in determining the presence/absence of consciousness. Central among such contexts are those that involve what we will call ‘challenging cases’—human infants, brain-damaged humans, non-human animals, and AI systems. There is a pressing need to identify measures of consciousness that can be applied to challenging cases. This talk examines one of the most promising strategies for identifying and validating such measures—the natural kind strategy. The talk is in two broad parts. Part I introduces the natural kind strategy, and contrasts it with other influential approaches in the field. Part II considers a number of objections to the natural kind approach, arguing that none succeeds.