3. The Origin of Common Sense

Dr Geoff Bunn's ten-part history is a journey through 5000 years of our understanding of the most complex thing in the known universe.

From Neolithic times to the present day, Geoff journeys through the many ideas of what the brain is for and how it fulfils its functions.

What soon becomes obvious is that our understanding of this most inscrutable organ has in all periods been coloured by the social and political expedients of the day no less than by the contemporary scope of scientific or biological exploration.

In this episode, the focus is on Ancient Rome with Galen's 'animal spirits' gently inflating the ventricles and making thought possible, and on how early Christian scholarship placed the soul in the brain's ventricles.

But with the Dark Ages, it was Islamic scholars who continued to explore the brain: Al Razi studied apoplexy or stroke, while Ibn Sina proposed that thoughts travelled through the brain in a predictable sequence and identified the 'common sense' in the front ventricle.

Featuring the voices of:

* Paul Bhattacharjee
* Jonathan Forbes
* Hattie Morahan

Producer: Marya Burgess

First broadcast on BBC Radio 4 in November 2011.