Whether or not the law of sufficient reason is a basic law of formal logic is a question that merits in-depth discussion. Back in the 1960s, when discussion was held on the object and function of formal logic, some comrades were of the opinion that formal logic should not be confined to the study of the form of thinking. One of their arguments was "the law of sufficient reason requires that the contents of the premise be true." Similarly, in the (...) discussion of the truthfulness and correctness of formal logic, some comrades also held that the correctness of the form of thinking and the truthfulness of its contents are a unity. Their opinion supposed that "it is one of the requirements of the law of sufficient reason that the reason must be true." All these discussions involved the nature of the law. Therefore the current discussion is a continuation and deepening of the previous discussions on logic. It involves not only the content of the law of sufficient reason as well as its role and position in formal logic, but also the object under the study of formal logic as a branch of science and the direction of its future development. Doubtlessly, the discussion of this issue bears major significance. (shrink)