Deletion of Is the glass half empty or half full?

Comment: per Byrgenwulf's comments. This is someone's personal essay. No sources are cited. Violates  and . If well-known sources are easy-to-find, please cite some
Stance: delete
Cited policy: Wikipedia:Verifiability (WP:V||WP:OR)

Comment: as a well-known and well-used idiom and theory.  Needs sources and some  cleanup; but well-written and informative
Stance: keep
Cited policy: Wikipedia:Verifiability (WP:V)