Inductive reasoning and deductive reasoning

Inductive reasoning is a kind of reasoning from individual to general. From a certain point of view about individual things to a larger point of view, the general principle and the explanation method of the principle are deduced from special concrete examples.

Deductive reasoning is a reasoning method from general to special. Contrary to induction. The connection between reasoning premise and conclusion is inevitable, and it is a kind of conclusive reasoning. Using this method to study problems, we must first correctly grasp the general principles and principles as guiding ideology or basis;

Secondly, we should fully understand the actual situation and particularity of the topics and problems to be studied; Then we can deduce the conclusion that general principles are applied to specific things.

Extended data:

There are differences and connections between inductive reasoning and deductive reasoning.

differentiate

1, the thinking process is different. The thinking process of inductive reasoning is from individual to general, while the thinking process of deductive reasoning is not from individual to general, but an inevitable thinking process.

Deductive reasoning is not from individual to general reasoning, but it is not only from general to individual reasoning: deductive reasoning can be from general to general, such as from "all unjust wars are unpopular" to "all unjust wars are unpopular";

From individual to individual, for example, from "roger bacon is not Bacon who established the new inductive logic theory" to "Bacon who established the new inductive logic theory is not roger bacon";

It can be inferred from individual, general to individual, such as "this thing is not conductive" and "all metals are conductive", that is, "this thing is nonmetallic";

It can also range from individual to average, such as "You are qualified for this job", "Where there is a will, there is a way" or "You are not qualified for this job".

What we should pay special attention to here is that the thinking process of complete inductive reasoning in inductive reasoning is not only from individual to general, but also inevitable.

2. Different requirements for the authenticity of premises. Deductive reasoning requires that the major premise and minor premise must be true. Inductive reasoning has no such requirement.

3. The range of knowledge reached by the conclusion is different. The conclusion of deductive reasoning is not beyond the scope of knowledge determined by the premise. In addition to complete inductive reasoning, the conclusion of inductive reasoning is beyond the scope of knowledge determined by the premise.

4. The relationship between premise and conclusion is different. The connection between the premise and conclusion of deductive reasoning is inevitable, that is to say, the premise is true, the reasoning form is correct, and the conclusion must be true.

In inductive reasoning, except that the connection between premise and conclusion is inevitable, the connection between premise and conclusion is probable, that is to say, the premise is true and the reasoning form is correct, but the real conclusion may not be deduced.

get in touch with

1, if deductive reasoning is based on general knowledge (deductive reasoning is not necessarily based on general knowledge), it usually relies on inductive reasoning to provide general knowledge.

2. Inductive reasoning is inseparable from deductive reasoning. First, in order to improve the reliability of inductive reasoning, it is necessary to use the existing theoretical knowledge to analyze the individual premise of inductive reasoning and grasp the causality and inevitability, which requires deductive reasoning.

Secondly, inductive reasoning relies on deductive reasoning to verify its own conclusions. For example, Russian chemist Mendeleev discovered the periodic law of elements through induction, and pointed out that the properties of elements change periodically with the increase of atomic weight of elements.

Later, through deductive reasoning, it was found that the atomic weights of some elements originally measured were wrong. So he rearranged their positions in the periodic table, predicted some undiscovered elements, and pointed out that blank positions should be reserved for new undiscovered elements in the periodic table.

In the history of logic, there have always been two opposing factions-the general inductive school and the general deductive school. The general inductive school regards induction as the only scientific way of thinking and denies the role of deduction in cognition.

The whole deductive school regards deduction as the only scientific way of thinking and denies the significance of induction. Both views are one-sided. As Engels said: "Induction and deduction, like analysis and synthesis, are bound to be interrelated.

We shouldn't sacrifice one and praise the other to heaven. We should use each one in its proper place. To this end, we must pay attention to their mutual connection and complementarity. "

References: Baidu Encyclopedia-Deductive Reasoning Baidu Encyclopedia-Inductive Reasoning