For example, a young person in good health and not in any special danger would usually be misguided in being pessimistic about his prospects for surviving to his next birthday. It is possible but unlikely that he will die before then. By contrast, the same young person would be rightly pessimistic about becoming a centenarian. It is possible but not likely that he will reach that age. Thus, there can be no generalized defense of either optimism or pessimism. We should be optimistic about some matters and pessimistic about others.
