For one who is indifferent, life itself is a prison. Any sense of community is external or, even worse, nonexistent. Thus, indifference means solitude. Those who are indifferent do not see others. They feel nothing for others and are unconcerned with what might happen to them. They are surrounded by a great emptiness. Filled by it, in fact. They are devoid of all hope as well as imagination. In other words, devoid of any future.
