Ages of compulsory retirement are fixed at point varying from 55 to 75, all being equally arbitrary and unscientific. Whatever age has been decreed by accident and custom can be defended by the same argument. Where the retirement age is fixed at 65 the defenders of this system will always have found, by experience, that the mental powers and energy show signs of flagging at the age of 62. This would be a most useful conclusion to have reached had not a different phenomenon been observed in organizations where the age of retirement has been fixed at 60. There, we are told, people are found to lose their grips, in some degree, at the age of 57.