It is necessary for every person who stands for progress to criticise every tenet of old beliefs. Item by item he has to challenge the efficacy of old faith. He has to analyse and understand all the details. If after rigorous reasoning, one is led to believe in any theory of philosophy, his faith is appreciated. His reasoning may be mistaken and even fallacious. But there is chance that he will be corrected because Reason is the guiding principle of his life. But belief, I should say blind belief is disastrous. It deprives a man of his understanding power and makes him reactionary.