basic laws of logic can be likened to the principles and rules applicable in nature.However, they have their own specifics, at least that do not operate in the world around us, and in the plane of the human mind.But on the other hand, the principles adopted in the logic, different from legal norms that they can not be undone.They are objective and act against our will.Of course, you can not argue according to these principles, but then these are reasonable inference is hardly anyone thinks.
logical laws - a pillar of science, both natural and human.If in everyday life you can still indulge in the flow of feelings that are incompatible with the rules of construction and the development of thought, you can avoid the logical gaps, the serious work or discussion of such an approach is unacceptable.For the foundation of all the principles of evidence are correct judgment.
What are these rules?Three of them were discovered in antiquity by Aristotle: the principle of consistency, the rule of identity and the law of the excluded middle.Centuries later, Leibniz discovered another principle - sufficient reason.All three laws of formal logic, described by Aristotle, are inextricably interconnected.If we assume for a moment that one link umopostroeny not, then, as a house of cards, and split the rest.
law of the excluded middle can be summarized as follows: «Tertium non datur» or «no third option."If we express two contradictory sentences concerning the same subject matter (or a series of objects or phenomena), one judgment will be true, and the other - no.Between these statements can not be built for some third, which would have brought together two major or served as a link between them logical bridge.The simplest example of the excluded middle: "This thing is white" and "This thing is not white."But it works only when the two opposing sentiments were expressed about the same things this time and on the same terms.
law of the excluded middle, and shall come into force when the judgments between A and B have contraries or kontradiktornaya incompatibility.The first - a statement of the opposite view.For example, judgments "Earth revolves around the sun" and "the sun revolves around the earth" are contraries.Kontradiktornoe contradiction arises when the phrase A claims and B denies that any "warm fire" and "fire does not warm."It is also a contradiction occurs between private and general judgments, when one positive and the other - a negative, "Some students already have diplomas" and "No student has a diploma."
to thinking, especially in science, special requirements: consistency, consistency determination.The law of the excluded middle - a measure of the truth of our reasoning.For example, if we say that "God - all-good", then the maxim "God gave eternal torments of hell for sinners" is meaningless.If we affirm that God created a place of eternal torment for someone else, then you can not claim that he - Good.As God as the object of our conclusions may not be held contrary to the signs, some of the above two sentences is true, then the second - false.Third is not given.
