1 / 8

Disjunctive Syllogism

Disjunctive Syllogism . Either/Or Statements . Parts. Major Premise: presents an “either/or” statement” with two alternatives Minor Premise: Denies or affirms one of the alternatives Conclusion . Valid Forms. Minor Premise: Denies one of the alternatives presented in major.

hamlet
Download Presentation

Disjunctive Syllogism

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Disjunctive Syllogism Either/Or Statements

  2. Parts • Major Premise: presents an “either/or” statement” with two alternatives • Minor Premise: Denies or affirms one of the alternatives • Conclusion

  3. Valid Forms • Minor Premise: Denies one of the alternatives presented in major. • Conclusion: Affirms the other alternative.

  4. Valid example • Bill will either pass Critical Thinking or he will fail. Bill did not pass Critical Thinking, so he failed. • Major Premise: Bill will either pass Critical Thinking (ALT #1) or he will fail (ALT #2). • Minor Premise: Bill did not pass Critical Thinking (Denies Alt. #1) • Conclusion: Bill failed.

  5. Invalid Form • Minor premise affirms one alternative offered in major premise • Conclusion denies the remaining alternative.

  6. Fallacy • A false disjunction (fallacy) occurs when the major premise limits the alternatives to only two, when further investigation indicates that other alternatives are still possible. • Major Premise: WHS students will either go to a university or a tech college upon graduation. • Minor Premise: That student will not go to a university. (denies one alternative) • Conclusion: That student will attend technical college. (affirms the other alternative)

  7. Invalid Example • Either you are for me 100% on this issue or you are against me and what I stand for. You are for me and what I stand for, so you are not against me on this issue. • Major Premise: Either you are for me 100% on this issue, or you are against me and what I stand for. • Minor Premise: You are for me and what I stand for. (affirms one alternative) • Conclusion: You are not against me on this issue. (denies the other alternative)

  8. The conclusion of a disjunctive syllogism can be accepted as truth if the argument satisfies the following conditions: 1) the minor premise correctly limits the two alternatives and 2) the argument is presented in a valid form.

More Related