Logical Reasoning Syllogisms and Three Types of Hypothetical

  • Slides: 6
Download presentation
Logical Reasoning Syllogisms and Three Types of Hypothetical Syllogisms

Logical Reasoning Syllogisms and Three Types of Hypothetical Syllogisms

Definition of A Syllogism A syllogism is a deductive argument presented in the form

Definition of A Syllogism A syllogism is a deductive argument presented in the form of two supporting premises and a conclusion. Premises and conclusion will be presented on separate lines with the conclusion last.

Two Types of Syllogisms �Hypothetical Syllogisms, is a form of deductive arguments that contain

Two Types of Syllogisms �Hypothetical Syllogisms, is a form of deductive arguments that contain two premises at least one of which is a hypothetical or “if…. , then …. . ” statement. �Categorical Syllogisms, is a deductive argument, in which categories or sorts things into specific classes, such as mammals, students, or countries. It is composed of a conclusion, two premises and three terms, each of which occurs exactly twice in two of the three propositions.

Three Types of Hypothetical Syllogisms �Modus Ponens , is a hypothetical syllogism in which

Three Types of Hypothetical Syllogisms �Modus Ponens , is a hypothetical syllogism in which the antecedent premise is affirmed by the consequent premise. Example: If A (antecedent), then B (consequent). A. Therefore, B. If I get the raise at work, then I will pay off my debt. I got the raise at work. Therefore, I will pay off my debt.

Three Types of Hypothetical Syllogisms �Modus Tollens, is a hypothetical syllogism in which the

Three Types of Hypothetical Syllogisms �Modus Tollens, is a hypothetical syllogism in which the second premise denies the consequent, and the conclusion denies the truth of the antecedent. Example If A (Ancedent), then B (Consequent). Not B. Therefore, Not A. If Jim is a lawyer, then he went to law school. Jim did not go to law school. Therefore, Jim is not a lawyer.

Three Types of Hypothetical Syllogisms �Chain Arguments, are hypothetical arguments in which three or

Three Types of Hypothetical Syllogisms �Chain Arguments, are hypothetical arguments in which three or more conditional premises are linked together. Example: If A, then B. If B, then C. If C, then D. Therefore, A, then D.