When you feel that you have reached a conclusion thanks to elements that have provided you with generic data, but clearly intended to reach that type of solution, it will be a deductive reasoning process. The elements of this thought are so connected to each other that through a series of logical considerations, conclusions and principles are reached that confirm the premise but do not provide new information.
In this Psychology-Online article we will explain in depth What is deductive reasoning, characteristics, types and some examples.
What is deductive reasoning
What is deductive reasoning? The deductive method or deduction is the rational procedure that allows reaching a conclusion of more generic premises in which that conclusion is implicit. The term literally means “to drive from”, because it comes from the Latin “de”, which translates as from, a preposition that indicates origin, or movement of descent from top to bottom, and “ducere”, which means to drive.
In the following article you will find the.
Characteristics of deductive reasoning
The introduction of the concept of deduction is due to Aristotle, who substantially identified it with the syllogism. This method is based on postulates and premises that, through a series of rigorous logical concatenations, proceeds towards more particular determinations related to tangible reality. Deductive reasoning is, therefore, reasoning in which the premises, if true, guarantee the truth of the conclusion.
In this way, the conclusion of correct deductive reasoning cannot be false, assuming that its premises are true. This is what it means to label reasoning as “valid” in logic. Likewise, the structure of deductive reasoning is a fundamental aspect to take into account when carrying out this type of reasoning.
Types of deductive reasoning
What are the types of deductive reasoning? Typical forms of deductive reasoning are syllogism and conditional reasoning (if…then). The structure of the syllogism is made up of two premises and a conclusion, the latter linked to the former by a relationship of logical necessity. The premises can be:
- Affirmative universals: all x are y.
- Negative universals: without x and y.
- Positive particulars: some x and y.
- Negative Particulars: some x is not y.
Examples of syllogism
Syllogisms are characterized by the 16 ways in which the structures of the premises can be combined and by the four figures that the middle term can assume, which is present in both premises but does not appear in the conclusion. Next, we show you a example of syllogismeither:
- All men are mortal;
- All Greeks are men;
- All Greeks are mortal.
However, there are cases in which the invalid syllogism is easily recognizable:
- All French people are men;
- All Spaniards are men;
- All Spaniards are French.
On the other hand, there are also other cases in which it is more difficult to detect an invalid syllogism, since the conclusion is factually true:
- All Spaniards love football;
- All Madrid residents love football;
- All Madrid residents are Spanish.
What errors does syllogistic deductive thinking present?
The most classic of deductive reasoning problems is characterized by the conditional syllogism, expressed by a major premise of the type “if p then q” and a minor premise represented by the affirmation or denial of antecedent and consequent: “p”, “not -q”, “q” and “no-p”. Therefore, there are four conditional syllogisms.
Most research on conditional reasoning has shown that people tend to fall into fallacies and they have more difficulty accepting the conclusion of the modus tollens as valid, but they do not have major problems with themes in modus ponens form.
The presence of fallacies and other types of errors has made deductive reasoning become a topic of interest, especially in recent decades, when human reasoning abilities began to be questioned.
Examples of deductive reasoning
A typical discipline that uses deductive thinking to arrive at solutions is the math. The mathematician reaches the rational conclusion that if he knows that the sum of the interior angles of a triangle is equal to 180 degrees and knows the measurements of two of the three, he will be able to deduce the amplitude of the third angle, without a triangle even if it has never appeared before your eyes.
In this sense, it is said that deductive reasoning is reasoning capable of expressing a judgment about the reality examined even before experiencing that reality. Returning to the triangle example, each of us can say that if the amplitude of two angles is 60 degrees, then the third will also be 60 degrees, regardless of whether the third angle has been measured with a protractor.
Difference between deductive and inductive reasoning
This process of knowledge, which to define with its specific term we will call gnoseological, is opposite of inductive reasoning. Both terms have their roots in the Latin language, an induction that derives precisely from “ducere” (to drive), preceded by the suffix “in” and which indicates a thought that is based on experience. Thanks to sensible reality, the data are introduced into the intellect and it elaborates them to obtain an abstract law, no longer a priori, but judging reality after experience.
The deductive method, unlike the , is based on an axiom, a principle or thought that is considered an absolute truth that does not necessarily have to be subjected to verification. From this, specific consequences that are valid as long as the premises are valid are deduced through reasoning. In this way, if the premises are disproved or shown to be not real, the entire validity of the reasoning would collapse. This detail is the main current criticism of the method, which is still being debated among philosophers of science and perhaps an absolute and universal truth will never be found.
This article is merely informative, at Psychology-Online we do not have the power to make a diagnosis or recommend a treatment. We invite you to go to a psychologist to treat your particular case.
If you want to read more articles similar to Deductive reasoning: what it is, characteristics, types and exampleswe recommend that you enter our category.
Bibliography
- Ruotolo, F. (2022). Thought, reasoning and decision. Retrieved from: https://www.psicologia.unicampania.it/images/FIT_24_CFU/materiali/PsicologiaGenerale/Gruppo4/Pensiero_ragionamento_e_decisione.pdf
- Unicusano (2018). Deductive ragionamento: ecco come funziona. Retrieved from: https://aosta.unicusano.it/studiare-a-aosta/ragionamento-deduttivo/