The paradox of beneficial retirement

Morally, when should one retire from one's job? The surprising answer may be 'now'. It is commonly assumed that for a person who has acquired professional training at some personal effort, is employed in a task that society considers useful, and is working hard at it, no moral problem arises about whether that person should continue working. I argue that this may be a mistake: within many professions and pursuits, each one among the majority of those positive, productive, hard working people ought to consider leaving his or her job.