Conditional Logic : Conditional Logic Mastering conditional reasoning is important
for doing well on the test Appears on all three parts of the test Deals with hypotheticals and counterfactuals, which are central to the legal profession
If someone is in law school then they took the LSAT : If someone is in law school then they took the LSAT If A then B Not a specific instance, but a relationship Relationship is that when the first thing is true, the second thing must be true as well Not a causal or temporal relationship
Slide 3 : If someone is in law school then they took the LSAT John is in law school. Therefore, John took the LSAT. Conditional statement is abstract, allows us to make concrete inferences
Slide 4 : If someone is in law school then they took the LSAT What follows ‘if’ is the sufficient condition It’s sufficient to make the other part happen, it guarantees it
Slide 5 : If someone is in law school then they took the LSAT What follows ‘if’ is the sufficient condition It’s sufficient to make the other part happen, it guarantees it What follows ‘then’ is the necessary condition It’s a necessary part or a requirement for the other part to happen
Slide 6 : If someone is in law school then they took the LSAT What follows ‘if’ is the sufficient condition It’s sufficient to make the other part happen, it guarantees it What follows ‘then’ is the necessary condition It’s a necessary part or a requirement for the other part to happen
Slide 7 : If someone is in law school then they took the LSAT What follows ‘if’ is the sufficient condition It’s sufficient to make the other part happen, it guarantees it But it’s not necessary for the other part to happen John is not in law school John could still have taken the LSAT
Slide 8 : If someone is in law school then they took the LSAT What follows ‘then’ is the necessary condition It’s a necessary part or a requirement for the other part to happen But it’s not sufficient for the other part to happen John took the LSAT John may not be in law school
Slide 9 : If someone is in law school then they took the LSAT John did not take the LSAT John is not in law school Another way of saying the conditional relationship is that the sufficient condition can’t be true if the necessary condition isn’t true
Slide 10 : If someone did not take the LSAT then they are not in law school John did not take the LSAT John is not in law school Another way of saying the relationship is that the sufficient condition can’t be true without the necessary condition being true Known as contrapositive If someone is in law school then they took the LSAT
Slide 11 : If someone is in law school then they took the LSAT If someone is not in law school then they did not take the LSAT X Sufficient condition is not a requirement Incorrect negation shows up frequently
Slide 12 : If someone took the LSAT then they are in law school X Necessary condition is not a guarantee Incorrect reversal also shows up frequently If someone is in law school then they took the LSAT
Slide 13 : Law sch. LSAT If someone did not take the LSAT then they are not in law school Law sch. LSAT If someone is in law school then they took the LSAT