Deductive reasoning is one of the many problem solving strategies used to draw conclusions about the things people perceive. Deductive reasoning seeks to understand problems by focusing on specific facts. It relies on general ideas to draw conclusions by utilizing top bottom processing. Deductive reasoning is an imperative mental process.
Deductive reasoning requires logic and reason to draw conclusions. According to Goldstein, deductive reasoning is a technique created by Aristotle. “The father of deductive reasoning is Aristotle, who introduced the basic form of deductive reasoning called the syllogism. A syllogism consists of two premises followed by a third statement called the conclusion. We will first consider categorical syllogisms, in which the premises and conclusion are statements that begin with All, No, or Some. An example of a categorical syllogism is the following:
Premise 1: All birds are animals. (All A are B)
Premise 2: All animals eat food. (All B are C)
Conclusion: Therefore, all birds eat food. (All A are C)” (Goldstein, 2015) Syllogisms exemplify the logic behind deductive reasoning. The ability to draw a conclusion based on two related premises is an ability people utilize daily.
The brain uses top-down processing to comprehend information in the order in which it is perceived. When using deductive reasoning, the brain perceives the first two premises and draws a conclusion. A general idea is presented (all birds are animals), compared to another idea (all animals eat food) and based on these two ideas, an observation is created (therefore, all birds eat food). From there, people may seek further evidence to prove their observation as truthful and valid.
For example, deductive reasoning might lead someone to draw conclusions that are not actually truthful. The arguments may be valid, but not sound. “Validity is about whether the conclusion logically follows from the premises. If it does, and the premises are true, as in Syllogism 1, then the conclusion will be true as well. But if one or both of the premises are not true, the conclusion may not be true, even though the syllogism’s reasoning is valid.” (Goldstein, 2015) Thus, validity does not equate to truthfulness. Deductive reasoning can therefore yield inaccurate conclusions.
Deductive reasoning is used often in life, such as to solve mathematical equations, draw conclusions about the people around us and to solve day to day issues. The use of top down processing is also often subconsciously used. To get the most out of deductive reasoning, it is best to prove the drawn conclusion. Doing so will strengthen arguments and build credibility, making the observer a more reliable source of information.
Goldstein, E. B. Cognitive Psychology: Connecting Mind, Research and Everyday Experience, 4th Edition. Cengage Learning, 2015. [CengageBrain Bookshelf].