Class Notes (834,640)
Canada (508,664)
Philosophy (1,795)
PHI1101 (485)
All (28)
Lecture

PHI1101_Tuesday__January_28th

5 Pages
94 Views
Unlock Document

Department
Philosophy
Course
PHI1101
Professor
All Professors
Semester
Fall

Description
Deductive ArgumentAccordingly if an argument has a An argument intended to provide logically combination of false premises and a false conclusive support for its conclusionconclusion it is still validThe defining characteristic of a deductive NB is west of Ontarioargument is that its valid or invalidEvery province west of Ontario is famous for harvesting lobsterA deductive argument is intended to provide Thus NB is famous for harvesting lobsterconclusive support for its conclusionFinal definite undeniable supportIf these premises were true they would The structure of some arguments is guarantee the valid conclusiondeductiveWhen arguments structured this way are This argument has a combination of false good they guarantee their conclusionpremises and a true conclusion Is it valid YesExamplesIf youre reading this statement you are All philosophers are smartaliveMacdonald is a philosopherYou are reading this statementSo MacDonald must be smartHence you are aliveCategorical syllogism This argument has a combination of true Im taller than Aimeepremises and a true conclusion Is it valid Aimee is taller than MelissaYesSo Im taller than MelissaArguments that are valid can be described If you drove through town you drove past as havingmy houseAnd you did drive right through townFalse premises and a false conclusionSo you must have driven right past my False premises and a true conclusionhouseTrue premises and a true conclusionIn each case if the premises offered really The only combination of premises and a are true then the conclusion must also be conclusion that a valid argument cannot true and we can therefore describe that have is true premises and a false argument as being validconclusionLook at this argument If an argument has true premises and a false conclusion then it is invalidPigs have wingsAny animal with wings can flyWe want to consider an informal test for So pigs can flyvalidity in which we try and imagine a scenario where the premises can be true The premises are both falseand the conclusion falseThe conclusion is also falseIf we can imagine such a scenario then the Do the premises support the conclusion argument is invalidYes the structure of the argument is validIf we cant imagine such a scenario then the argument is valid
More Less

Related notes for PHI1101

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit