Logic is the part of philosophy that analyzes the laws governing thought. Basically, the science of reasoning and argumentation. In discussions between two individuals who hold opposing arguments is an essential tool to enable them to reach an agreement. The classic principles of logic were raised by Aristotle. The Greek philosopher maintained that logical reasoning is what allows us to get a true conclusion from two true judgments. With the evolution of philosophy, logic was linking the theory of knowledge. There was also a correspondence between the logic and mathematics. The new discipline that faith gesture is called formal logic. The main speakers of this discipline in the twentieth century thinkers were Bertrand Russell and Alfred North Whitehead.
Modern logic, called formal, symbolic language used subject to rules. The student of logic makes symbolic systems regardless of the relationship they may have with reality. Later, the researchers apply these symbolic systems to the study of positive sciences and can move in them, knowing that they will be arguing wrongly.