In order to give ourselves a mental picture of these three logical processes, let us think of a man walking. In order to get from, say, one room to another, he has to pick up his foot and take several steps in order to get to the room that is his destination. Taking a full step is like making a judgement. We said logic was one of three divisions of philosophy, the others being theoretical philosophy and practical philosophy. We said there are two main branches of logic, one called formal or minor logic, the other material or major logic.
Material logic is concerned with the content of argumentation.
Formal logic is interested in the form or structure of reasoning. Therefore, we concluded, while the conclusion of a deductive argument is conclusive , the conclusion of an inductive argument is only probable . We defined truth as correspondence with reality. We said an argument is valid when its conclusion follows logically from its premises. And we said that soundness indicates that all the premises in an argument are true and that the argument is valid.