In a syllogistic argument: All humans are mortal. Socrates is a human. Therefore, Socrates is mortal. What type of reasoning is this?

• A. Inductive reasoning
• B. Abductive reasoning
• C. Deductive reasoning; valid syllogism.
• D. Analogical reasoning

Answer: (C)

Deductive reasoning: this kind of argument uses a general rule and a specific instance to reach a conclusion that must be true if the premises are true. Here, the universal rule “All humans are mortal” is applied to the specific case “Socrates is a human.” Since Socrates fits the rule, the conclusion “Socrates is mortal” follows necessarily. This is a classic categorical syllogism, where a general statement about a class and a member of that class yields a conclusion about that member, and the conclusion is guaranteed given the premises.

It isn’t inductive reasoning, which would move from specific observations to a generalization with uncertainty. It isn’t abductive reasoning, which looks for the best explanation for observations. It isn’t analogical reasoning, which draws conclusions based on similarities between cases.