This is a podcast from the archives of the BBC Reith Lectures.

This lecture in the series Mechanics of the Mind, given by Colin Blakemore, was originally broadcast in 1976.

1848 was a year of revolution in Europe.

Karl Marx and Friedrich Engels published the Communist Manifesto and political demonstrations tore apart the great cities of Paris, Vienna, Naples and Berlin.

That same year, in New England, a bizarre accident touched off a minor revolution of a different sort,

not a radical change in man's attitude to man,

but a turning point in his understanding of that part of man

which fosters social conscience, his mind.

The accident occurred at about 4.30 in the afternoon of the 13th of September, 1848,

near the small town of Cavendish, Vermont.

A gang of men, under the direction of their energetic and likable foreman,

25-year-old Phineas P. Gage, was working on the new line of the Rutland and Burlington Railroad.

They were about to blast a rock that blocked their way,

and Phineas himself took charge of the delicate business of pouring gunpowder

into a deep narrow hole drilled in the stone.

The powder in place, he rammed in a long iron rod to tamp down the charge before covering it with sand.

But the tamping iron rubbed against the side of the shaft and a spark ignited the powder.

The massive rod, three and a half feet long, an inch and a quarter in diameter, weighing 13 pounds,

shot from the hole under the force of the explosion.

This terrible missile struck Phineas gauge just beneath beneath his left eye, and in a fraction of

time tore through his skull, departed from a hole in the top of his head, and finally landed some

50 yards away. Believe it or not, that was not the end of Phineas P. Gage, at least not of the body

...