Difference between deduction and induction.

Life constantly forces us to make decisions. And few people think that reflections on what is happening are based on very specific schemes. We will reveal this topic in more detail, or rather, we will find out how deduction differs from induction.


Deduction is an argument in which the existing premises (statements) become the basis for the conclusion. Example: any number that is a multiple of four is divisible by two (premise); eight is a multiple of four (premise); therefore, eight is divisible by two (conclusion).

Induction is a mental method in which a certain general picture is drawn on the basis of single facts. Example: raspberries are sweet, strawberries are sweet, grapes are sweet; raspberries, strawberries, grapes - berries; it means that all the berries are sweet.


These are two opposite ways of thinking. The typical model of deduction assumes movement in some reasoning from the general to the particular. In induction, on the other hand, knowledge about individual units leads to the conclusion that all objects in this series have the same characteristics.

The difference between deduction and induction is that in the reasoning carried out in the first way, pure logic operates. This allows you to draw unmistakable conclusions. But there is one condition: the original positions must be true. Here's an example: any drink is a liquid (valid premise); compote is a drink (reliable premise); from this it follows that compote is a liquid (true conclusion).

In turn, the inductive inference is deduced not strictly in accordance with logic, but through guesswork and some representations. As a result, the obtained consequence is only probabilistic and requires verification. Even with true premises, the wrong conclusion can be obtained here. Example: Misha is a kindergartener, Kostya is a kindergartener, Sveta goes to kindergarten (true); Misha, Kostya, Sveta are children (true); all children attend kindergarten (lie - there are those who are at home before school).

It should be noted that the most reliable knowledge is given by full induction - the one in which each of a specific class of objects is investigated, and only after that a general judgment about the set is formed. But in practice, this is not always possible. Often, only the particular is considered, and then the definition is carried over to the entire group. In order for such conclusions to leave no doubt about their veracity, it is necessary to resort to repeated experiments and apply theoretical thinking.

Concluding the conversation on the topic of what is the difference between deduction and induction, it is worth mentioning that in scientific research, the two described methods are organically linked. Many important hypotheses are put forward by induction, and deduction allows one to obtain consequences from them that must be substantiated or refuted.