For the average five-year-old, you might expect playtime rather than Plato to be upmost in their thoughts.

But now the sound of neo-Socratic dialogue can be heard in primary school classrooms throughout the land as infants debate life's great mysteries in philosophy lessons.

Children as young as five are grappling the big questions that have troubled speculative thinkers from Aristotle through to Darwin, Freud and Kant.

Philosophy lessons are being introduced in dozens of primary schools in a bid to get more children reading and open their minds.