Obsession (n.) attacks what we love most: the most hideous thoughts fasten precisely on the objects most valued by our feelings.
Obsession (n.) is the secret of success — of a sort — which is why our civilization assiduously fosters it.
A Obsession (n.) is instinct gone underground: the man wholly ruled by instinct has an unconscious that blows instinct up into a universal principle; the man of ideas finds his instinct making his ideas its instruments.
Obsession (n.) is a cancer that will not kill the body but will eventually kill the soul, until you are no longer a human being but a tumour.
Obsession (n.) has not vanished, only been renamed for the worse: the primitive is plagued by a ghost, the professor by a cancer that dozens of X-rays cannot find — "but there still might be something."