Almost every object of knowledge has a branch of knowledge which studies it. Planets, stars, and galaxies are studied by astronomy. Chemistry studies the structure, composition, and properties of material substances and the transformations they undergo. The origin, evolution, and development of human society is the object studied by sociology. Economics, biology, geography, and grammar all have objects of knowledge which they investigate, describe, and try to explain.
Critical thinking involves a knowledge of the science of logic, including the skills of logical analysis, correct reasoning, and understanding statistical methods. Critical thinking, however, involves more than just an understanding of logical procedures. A good critical thinker must also understand the sources of knowledge, the nature of knowledge, and the nature of truth. But first, what is the science of logic?
The object of knowledge involved in the science of logic is "thinking," but it is "thinking" approached in a special way. Generally speaking, logic is that branch of knowledge which reflects upon the nature of "thinking" itself. But this may confuse logic with other branches of knowledge which also have the nature of "thinking" as a part of their specific object of investigation. We need a more detailed and accurate definition to eliminate any confusion.
Logic doesn't just deal with "thinking" in general. Logic deals with "correct thinking." Training in logic should enable us to develop the skills necessary to think correctly, that is, logically. A very simple definition would be: Logic is the subject