The character's name comes from two sources: Peter Llewelyn Davies, one of the five Llewelyn Davies boys who inspired the story, and Pan, a minor deity of Greek mythology who plays pipes to nymphs and is part human and part goat. This is referenced in Barrie's works (particularly Peter Pan in Kensington Gardens) where Peter Pan plays pipes to the fairies and rides a goat. The god Pan represents Nature or Man's natural state in contrast to Civilisation and the effects of upbringing on human behaviour. Peter Pan is a free spirit, being too young to be burdened with the effects of education or to have an adult appreciation of moral responsibility. As a 'betwixt-and-between', who can fly and speak the language of fairies and birds, Peter is part animal and part human. According to psychologist Rosalind Ridley, by comparing Peter's behaviour to adults and to other animals, Barrie raises many post-Darwinian questions about the origins of human nature and behaviour. As 'the boy who wouldn't grow up', Peter exhibits many aspects of the stages of cognitive development seen in children and can be regarded as Barrie's memory of himself as a child, being both charmingly childlike and childishly solipsistic.