Sir

The argument over evolution versus intelligent design, discussed in your News story “Day of judgement for intelligent design” (Nature 438, 267; 2005), is a relatively small-stakes theological issue compared with the potential eruption in neuroscience over the material nature of the mind.

Siding with evolution does not really pose a serious problem for many deeply religious people, because one can easily accept evolution without doubting the existence of a non-material being. On the other hand, the truly radical and still maturing view in the neuroscience community that the mind is entirely the product of the brain presents the ultimate challenge to nearly all religions.

The slow ramping up of this debate, from Descartes' dualism in the seventeenth century to the neurophilosopher materialists' claims of victory today, is about to spill over from an esoteric mind–brain debate to the divisive question of whether a product of the mind, such as God, can have any traditionally valid existence whatsoever.

The debate becomes whether a deity, on one hand, stems from human imagination or biological drive or, on the other hand, has an authentic existence that the brain has evolved to perceive.

The reappearance of dualism brings back dusty old memories of long-ago battles that may now need to be refought. As we saw from the media ruckus raised by the Dalai Lama's address to November's Society for Neuroscience meeting in Washington DC (even if this did turn down to a rather low simmer on site), the potential for impassioned disagreement exists.

The matter now stands at an intellectual impasse, waiting for an issue around which polarized views will crystallize. We can expect some heady days.