Chapter 63 [Chapter VII Sophistry in Deductive Reasoning] [Introduction]

Reasoning is the thinking process of deriving new knowledge from existing knowledge, and it is an indirect understanding of reality.Reasoning is made up of judgments.In reasoning, the judgment as existing knowledge is called the premise of reasoning, and the judgment as inferred knowledge is called the conclusion of reasoning.In addition, there is a way of connecting premises and conclusions, which is called the form of reasoning. Formal logic divides reasoning into deductive reasoning and non-deductive reasoning according to whether the conclusion of the reasoning is inevitable, and in non-deductive reasoning, it is further divided into incomplete inductive reasoning and analogical reasoning (these two kinds of reasoning will be introduced later).The characteristic of a correct deductive reasoning is that the premise implies the conclusion, that is, if the premise is true, the conclusion must be true; the characteristic of non-deductive reasoning is that the premise does not imply the conclusion, that is, the premise is true and the conclusion is not necessarily true, but the conclusion may be false.

A correct deductive reasoning must meet two conditions at the same time: first, the premise is true; that is, the ideological content of the premise is consistent with the objective reality; second, the reasoning form is correct, that is, the reasoning follows the rules of reasoning and logic. law.Inferences with false premises or wrong forms of reasoning are incorrect inferences, and the truth or falsehood of the conclusions of incorrect inferences is uncertain. Whether the premise of reasoning is true or not depends on various specific sciences, and ultimately depends on practice. Formal logic only requires that the premise must be true.Whether the form of reasoning is correct or not is a special study of formal logic, which can help us determine whether the form of reasoning is correct or not.The correct form of reasoning can not only ensure that the true conclusion must be drawn from the true premise, but also help to expose the fallacy in the premise, that is, when the false reasoning form of the conclusion is correct, we can conclude that there must be a false premise.

The sophistries played by the sophists in deductive reasoning, from a broad perspective, are, first, the deliberate application of false or one-sided premises, and second, the application of wrong forms of reasoning.Its specific manifestations are various, and we will disclose them in the following combined with example analysis.