Plato talked of prisoners watching shadows on a wall and picturing the outside world from what they saw projected there. Not picturing it very clearly.
This afternoon, a low sun was shining through the birch tree, casting intricate shadows upon the gable end of next door. Two shadows were more mobile than the rest. Up and across the wall they went, tails flicking. Magpies, instantly recognisable even in monochrome. I could picture them very clearly indeed!