Benjamin Libet, 1916-2007
I first read about Benjamin Libet’s famous experiments ‘disproving’ the existence of free will in Daniel Dennett’s outrageously named (but excellent) book Consciousness Explained (I was once at a book signing in Chicago where Daniel Dennett, promoting his psychology/sociology of religion book Breaking the Spell, mentioned that he thought Pascal Boyer’s biology/anthropology of religion treatise Religion Explained had a great title, and I’ve only just realised that he must have been thinking of Consciousness Explained when he said that). I was fascinated by those experiments and regarded them as a strong (although not conclusive) blow against the existence of free will as we conventionally think of it (Dennettian compatibilist free will is compatible with Libet’s experiments, but many don’t consider Dennett’s idea of what free will is as, well, free will at all). Libet’s recent passing is hence a good excuse to quote from the abstract of his seminal paper:
The recordable cerebral activity (readiness-potential, RP) that precedes a freely voluntary, fully endogenous motor act was directly compared with the reportable time (W) for appearance of the subjective experience of ‘wanting’ or intending to act. The onset of cerebral activity clearly preceded by at least several hundred milliseconds the reported time of conscious intention to act.
[...]
It is concluded that cerebral initiation of a spontaneous, freely voluntary act can begin unconsciously, that is, before there is any (at least recallable) subjective awareness that a ‘decision’ to act has already been initiated cerebrally. This introduces certain constraints on the potentiality for conscious initiation and control of voluntary acts.
I read in Susan Blackmore’s obituary for Libet that he’d done subsequent experiments showing that “we may not be able to start actions consciously, but we can veto them once they have begun – saving at least some role for free will”. More papers to put on my reading list, then.
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