A belief is healthy if it catalyzes positive emotion. Negative, self-defeating or self-deprecating beliefs are unhealthy because they catalyze emotional distress and bodily stress, which is very bad for our health and wellbeing. Although negative thinking is unhealthy, positive thinking can be extremely difficult to achieve when you are not feeling well or things in your life are not going well. Negative thoughts and beliefs are only harmful when you view them as factual. The best way to work with negative thinking is to learn how to distance yourself from those unhealthy thought patterns. Learn to view thoughts as nothing but insubstantial mental concepts; don’t buy into them.