An ABC report investigates dreams and the philosophical questions they raise.

The concept of dreams and dreaming certainly stirred up 17th century French philosopher Rene Descartes.

Descartes’ problem is really the most famous: ‘how can I ever be sure that I’m not dreaming right now, that I’m really awake?’

‘If I can’t tell the difference, as Descartes thinks we can’t between dreaming and wakefulness, then how can I ever really trust my sensory-based beliefs about the world?’ asks Jennifer Windt, philosophy lecturer at Monash University.

Get the full story at www.abc.net.au