![Page 1: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/1.jpg)
![Page 2: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/2.jpg)
Sentence(syntacticallyIndependent
grammatical unit)
Question Command Statement
“This is a class
in logic.”“I enjoy logic.” “Today is
Friday.”
![Page 3: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/3.jpg)
Argument
• Argument is an attempt to persuade someone of something, by giving reasons or evidence for accepting a particular conclusion
![Page 4: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/4.jpg)
Premise
A premise is a statement that an argument claims will induce or justify a conclusion
![Page 5: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/5.jpg)
How to Recognize Arguments?How to Recognize Arguments?
![Page 6: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/6.jpg)
Conclusion Indicators
• Therefore• Hence• Thus• So• Accordingly• In consequence• Proves that• As a result• For this reason
![Page 7: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/7.jpg)
Premise Indicators
• Since• Because• For• As• Follows from• As shown by• Inasmuch as
![Page 8: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/8.jpg)
![Page 9: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/9.jpg)
![Page 10: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/10.jpg)
Argument Vs Explanation
• Premise – P• Conclusion – Q
![Page 11: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/11.jpg)
“Q because P”
![Page 12: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/12.jpg)
Validity
Validity refers to a relation between propositions.
![Page 13: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/13.jpg)
Validity
• Validity never applies to any single proposition by itself.
![Page 14: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/14.jpg)
Validity
• P -> Q• Logical Necessity• Deductive/Inductive?
![Page 15: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/15.jpg)
Truth & Falsity
• Truth and Falsity are attributes of individual propositions.
![Page 16: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/16.jpg)
Valid Vs True
Truth and falsity are attributes of individual propositions or statements, validity and invalidity are attributes of arguments.
![Page 17: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/17.jpg)
Valid Arguments, True Propositions
• All mammals have lungs• All whales are mammals• Therefore all whales have lungs
![Page 18: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/18.jpg)
Valid Arguments, False Propositions
• All four-legged creatures have wings.• All spiders have four legs.• Therefore, all spiders have wings.
![Page 19: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/19.jpg)
Invalid Arguments, True Propositions
• If I owned all the gold in Fort Knox, then I would be wealthy.
• I do not own all the gold in Fort Knox.• Therefore, I am not wealthy
![Page 20: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/20.jpg)
Invalid Arguments, True Premisses, False Conclusion
• If Bill Gates owned all the gold in Fort Knox, then Bill Gates would be wealthy.
• Bill Gates does not own all the gold in Fort Knox.
• Therefore Bill Gates is not wealthy
![Page 21: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/21.jpg)
Valid Arguments, False Premisses, True Conclusion
• All fishes are mammals.• All whales are fishes.• Therefore all whales are mammals.
![Page 22: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/22.jpg)
Invalid Arguments, False Premisses, True Conclusion
• All mammals have wings• All whales have wings.• Therefore, all whales are mammals.
![Page 23: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/23.jpg)
Invalid Arguments, False Premisses, False Conclusion
• All mammals have wings• All whales have wings• Therefore all mammals are whales
![Page 24: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/24.jpg)
Lessons
• When an argument is valid, and all of its premisses are true, we call it “sound”.
![Page 25: Sentence (syntactically Independent grammatical unit) QuestionCommandStatement “This is a class in logic.” “I enjoy logic.” “Today is Friday.”](https://reader035.vdocument.in/reader035/viewer/2022062905/5a4d1af17f8b9ab05997e333/html5/thumbnails/25.jpg)
Lessons
• Truth or falsity of an argument’s conclusion does not by itself determine the validity or invalidity of that argument.
• The fact that an argument is valid does not gurantee the truth of its conclusion.
• If an argument is valid and its premisses are true, we may be certain that its conclusion is true also.
• If an argument is valid and its conclusion is false, not all of its premisses can be true.