The law of the excluded third is the basic principle of logic

The basic logical laws can be likened to the principles and rules that operate in nature. However, they have their own specifics, at least in the fact that they do not act in the world around us, but in the plane of human thinking. But, on the other hand, the principles adopted in logic differ from legal norms in that they can not be canceled. They are objective and act in addition to our will. Of course, one can not argue according to these principles, but then these conclusions are hardly reasonable to anyone.

The logical law is a pillar of science, both natural and humanitarian. If in everyday life you can still indulge in a stream of feelings incompatible with the rules of constructing and developing thought, you can allow logical gaps, then in serious works or discussions such an approach is unacceptable. For the foundation of any evidence base is the principles of true judgment.

What are these rules? Three of them were discovered in the ancient era by Aristotle: this is the principle of consistency, the rule of identity and the law of the excluded third. After a century, Leibniz discovered another principle - a sufficient reason. All three laws of formal logic, described by Aristotle, are inextricably linked. If we admit for a moment that one link of mentalities is absent, then, like a house of cards, the rest also fall apart.

The law of the excluded third can be briefly stated as follows: "Tertium non datur" or "The third is not given." If we express two opposite sentences concerning the same object (or a series of objects or a phenomenon), then one judgment will correspond to the truth, and the other will not. Between these statements it is impossible to build yet another third that would reconcile the two main or serve as a connecting logical bridge between them. The simplest example of the excluded third: "This thing is white" and "This thing is not white." But it works only when both opposite sentences were expressed about the same thing, about the given time and about the same attitude.

The law of the excluded third comes into force also when there is a contradictory or counter-dictate incompatibility between judgments A and B. The first is a statement of the opposite point of view. For example, judgments "The Earth revolves around the Sun" and "The Sun revolves around the Earth" are contrarian. A contradictory contradiction arises when a phrase A claims, and B denies something: "Fire heats" and "Fire does not heat." Also this contradiction comes between private and general judgments, when one is positive, and the other is negative: "Some students already have diplomas" and "No student has a diploma".

To thinking, especially scientific, special requirements are put forward: consistency, consistency of certainty. The law of the excluded third is the measure of the truth of our logical reasoning. For example, if we say that "God is All-Good," then the maxim "God has made eternal hell torments for sinners" is meaningless. If we affirm that God created the place of eternal torment for anyone, then it can not be asserted that He is Good. Since contradictory signs can not belong to God as the object of our conclusions, one of the two sentences above is true, while the second is false. The third is not given here.