Lyric discussion by ohhallo 

As with most Pink Floyd albums, being the finest purveyors of the concept album, this song should be taken in context of the themes running throughout. It's a physical/spiritual/political journey from:

Silence, Depression, Despair, Loss, Separation (both inner between mind and soul, The Berlin Wall and a specific relationship) to Finding a Voice, Joy, Hope, Rediscovery, Re-unification (of inner self and East/West)

The hopeful tone in this song comes from the point where he takes a purposeful step out of Plato's cave 'into the shining sun' in a quest for real meaning, in the hope that it is there to be found.

I think the Berlin Wall/Iron Curtain reference is justified later on in the album in the song High Hopes which seems to be a nostalgic reminiscence of life before the wall fell: 'The grass was greener, the lights were brighter'. Speak to any former East German or watch the film 'Goodbye Lenin' and you will see what I mean...

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