Neuroscience and free will: religion and science do not always disagree

Tom Chivers' lively description of his interview with neuroscience professor Patrick Haggard highlights the fundamental question of whether brain research undermines our belief in free will and responsibility. Our brains determine our thinking and behaviour, and our neurons obey the laws of physics and chemistry, so how are we different from neural machines? As Tom points out in a second article, a lot depends on how you define free will.

On this issue, philosophers are divided into two camps: “libertarians“and “compatibilists”. For libertarians, free will is almost by definition incompatible with brain determinism. They argue from our experience of making choices that somewhere in the brain there must be indeterminate events. Most modern libertarians, including Robert Kane, invoke Heisenbergian uncertainty as the source of brain indeterminism, despite scepticism among scientists. In contrast, compatibilists argue for a different definition of free will. They make the distinction between external and internal constraints. The difference is illustrated by the following two excuses: “It’s not my fault I broke the window, my brother pushed me”, and “It’s not my fault I broke the window, my brain caused me to do it”.

Few people would accept the second excuse, which seems strange at best. If my brain did not cause me to break the window, I was certainly not responsible, so how can brain causation be an excuse? Of course, simple arguments like this are only a start in a complicated debate, but compatibilists are currently in the majority in claiming that the “varieties of free will worth wanting” (to quote Dennett) do not require indeterminate events in the brain. The debate is by no means over.

Our attitude to the free will question is intimately linked to the dualism-monism debate. Dualists believe that there are two separate entities, soul (or mind) and brain, and most maintain that they somehow interact, following Descartes. Monists deny a separate soul, saying that everything is matter. This links in with the question of free will, because if you believe in a separate nonphysical soul/mind that somehow influences the brain, you must assume that conventional physical and chemical forces do not completely determine brain function.

This debate is sometimes caricatured as a rearguard defense by religious or spiritually minded traditionalists against the attacks of modern science and atheistic philosophy, but there is not such a neat dividing line. The first philosophers to invoke physical indeterminism as necessary for free will were the materialists Epicurus and Lucretius, who denied life after death and supernatural intervention in the world. Judaism was monistic throughout the Old Testament era, and early Christianity appears likewise.

Read more at The Telegraph