Conviction has also four aspects to guard oneself against infatuations of sin; to search for explanation of truth through knowledge; to gain lessons from instructive things and to follow the precedent of the past people, Because whoever wants to guard himself against vices and sins will have to search for the true causes of infatuation and the true ways of combating them out and to find those true ways one has to search them with the help of knowledge, whoever gets fully acquainted with various branches of knowledge will take lessons from life and whoever tries to take lessons from life is actually engaged in the study of the causes of rise and fall of previous civilizations.