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Objection 15 · Neuroscience of the divine

Religious experience is just brain chemistry.

The objection, in full

Stimulate the temporal lobe, get a mystical experience. Take psilocybin, meet God. Epileptic seizures produce conversions; brain tumors produce visions of angels. If we can reliably trigger encounters with the sacred by poking neurons, the encounters tell us about the neurons, not the sacred.

Mystical experience tells us about the brain, just as a dream tells us about the dreamer.
— paraphrase of contemporary cognitive science of religion

or, in plain terms —If a brain scan can show why someone "feels" God, isn't God just in their head?

Thomas Aquinas
scholastic, the Five Ways
1225–1274

The soul is the form of the body. Of course the brain is involved.

The objection presupposes a Cartesian dualism that the Church never taught. It imagines the soul as a ghost attached to a body, and triumphantly announces that touching the body affects the ghost. But the human person is not a ghost in a machine. The soul is the form of the body — the principle by which this matter is this living, thinking person. Naturally, then, what affects the body affects the person, including in his perception of God.

That a stroke can change personality, that a tumor can produce visions, that psilocybin can occasion mystical experience — none of this is news to a Thomist. The intellect, in this life, depends on the senses and on the brain. Nihil in intellectu nisi prius in sensu. We always know God through the body, never apart from it.

What the neuroscientist can show is that religious experience uses the brain. He cannot show, by neuroscience alone, that the brain generates the object rather than perceives it. That is a philosophical claim, not a neurological one.

Citations Summa Theologiae I.75–76 (on soul and body) · ST I.84 (on knowledge through the senses)
Ad maiorem Dei gloriam