Knowledge limitations [repost]

For some reason[s], several posts have disappeared. So here is a repost.April 4th, 2008"Ode On A Grecian Urn"John Keats Thou still unravished bride of quietness,Thou foster child of silence and slow time,Sylvan historian, who canst thus expressA flowery tale more sweetly than our rhyme:What leaf-fringed legend haunts about thy shapeOf deities or mortals, or of both,In Tempe or the dales of Arcady