What are the three laws of logic?

(I) The Law of Identity

The basic content of the Law of Identity is that in the same thought process, each thought must be identical in itself. The formula for the same law is: "A is A". The A in the formula can denote any thought, i.e., it can denote any concept or any proposition. That is, each concept or judgment used in the same thought process has its definite content and cannot be arbitrarily transformed.

(ii)Law of Contradiction (Negative)

The Law of Contradiction is actually the Law of the Prohibition of Contradiction, or the Law of Non-Contradiction. The basic content of the law of contradiction is that two contradictory or opposing ideas in the same thought process cannot be true at the same time.

Or rather, a thought and its negation cannot be true at the same time. The formula for the law of contradiction is: not (A and not A). In the formula, "A" denotes any proposition, and "not A" denotes a proposition that is in contradiction or opposition to A. Thus, "not (A and not A)" is not a proposition. Thus, "not (A and not A)" means that the two propositions A and not A cannot be true, i.e., one of them must be false.

(3) The Law of Exclusion

The Law of Exclusion is based on the idea that two contradictory ideas in the same thought process cannot be false, but one must be true. The formula for the law of exclusion is: "A or not A".

The main function of the law of exclusion is to ensure the clarity of thought. And clarity of thought is a necessary condition for correct thinking. The logical requirement of the law of platitude is that for two contradictory judgments, one of them must be clearly affirmed to be true, and neither of them must be denied at the same time.

Fundamental laws of traditional logic:

About the fundamental laws of traditional logic, the ancient Greek philosopher and logician Aristotle clearly put forward two fundamental laws of traditional logic: the law of contradiction and the law of exclusion. contradiction) and the law of the center of the row.

Subsequent generations have organized the principle of the same law in Aristotle's remarks. There are also some logicians who believe that the law of sufficient reason proposed by Leibniz is also a fundamental law of logic. So the four basic laws are: the law of contradiction, the law of exclusion, the law of identity and the law of sufficient reason.