Now, cognition requires a judgment, that is, a proposition, which, without fail, has a subject and predicate which explain the object of cognition. Moreover, the proposition has a copula which signifies by words the relationship between subject and predicate, or in what manner they are connected with each other, regardless of whatever the object of cognition may be. Now, concepts which indicate the object of cognition, that is, subject and predicate, are the content, whereas the copula, which signifies the mode of the relationship between the two, is the form. Formal logic does not deal with the content of thinking, but only with the law and form of thinking. Law refers to the principle of identity, the principle of contradiction, the principle of sufficient reason, etc.
Form is inference form, which refers to direct inference and indirect inference.
Direct inference is an inference in which we draw a conclusion directly from one premise. Indirect inference is an inference in which we draw a conclusion from two or more than two premises, that is, major and minor premises. In the case of indirect inference, there are the deductive method and the inductive method. The logic of communism implies the logic of the dialectic method. Its main characteristic is that it deals with the developing movement of objective reality.