[originaltext] How to Avoid Foolish Opinions

How to Avoid Foolish Opinions
     To avoid the various foolish opinions to which mankind is prone, no superhuman genius is required. If the matter is one that can be settled by observation, make the observation yourself. Many matters, however, are less easily brought to the test of experience. If you have passionate convictions on many such matters, there are ways in which you can make yourself aware of your own bias.
     If an opinion contrary to your own makes you angry, that is a sign that you are subconsciously aware of having no good reason for thinking as you do. So whenever you find yourself getting angry about a difference of opinion, be on your guard; you will probably find that your belief is going beyond what the evidence warrants. A good way of ridding yourself of certain kinds of prejudice is to become aware of opinions held in social circles different from your own.