The more the mind is allowed to go on without purpose, the more likely it is to become a vehicle or machine, which all manner of influences around it of other human beings or spirit obsessions will employ instead of its owner. If the user of that mind is a sensible person, then it may perhaps act properly, but otherwise the work of the mind is wasted. In any case it would not be a fulfillment of the purpose of his life. This purpose is to learn mastery, not to be a vehicle for others to use. He who does not direct his own mind lacks mastery.