Philosophy 151:
Lots Of Logic Examples Handout
 


 
 
 

Lots Of Logic Examples
PHIL 151 - SPRING 2001
NOTE: The numbers and letters refer to the outline of the lecture.
B. LOGIC
2. Deductive arguments

EXAMPLE 1:
  P1 All men are mortal
  P2 Socrates is a man
   C Socrates is mortal
EXAMPLE 2:
  P1 Bananas are yellow
  P2 Lettuce is green
  C Tomatoes are red
EXAMPLE 3:
  P1 If any animal has four legs, then it has more than three legs.
  P2 All animals are either alive or dead.
  C All animals have moral rights.
EXAMPLE 4:
  P1 All bananas are purple.
  P2 All lettuce is orange.
  C All bananas and lettuce are either purple or orange.
EXAMPLE 5:
  P1 If any animal is red, then it has ears
  P2 If any animal has ears, then it has four legs
  C If any animal is red, then it has four legs.
EXAMPLE 6:
  P1 If you saw "The Terminator", you've seen Arnold Schwarzenegger.
  P2 You haven't seen Arnold.
  C You didn't see "The Terminator".

Be sure to do the logic exercises in the course pack - they'll help you to understand this stuff. The answers to those exercises are in the back of the course pack.

3. Inductive arguments
EXAMPLE 7:
  P1 This swan is white.
  P2 That swan is white.
  Pn Nth swan is white.
  C All swans are white.
EXAMPLE 8:
  P1 In the past, when I've gone home, my house has still been there.
  C When I go back home this afternoon, my house will still be there.
 

C. PRACTICE IN LOGIC: SOME QUICKIE ARGUMENTS FOR & AGAINST THE EXISTENCE OF GOD

1.
P1 The Bible says God exists.
C God exists.
2.
P1 The Bible is the word of God.
P2 The word of God is always true.
P3 The Bible says that God exists.
C God exists.
3.
P1 My parents have taught me that God does not exist.
P2 Mom wouldn't lie.
C God does not exist.
4.
P1 If there are trees and flowers then there exists a God who created them.
P2 There are trees and flowers.
C God exists.
5.
P1 If science can't explain something (such as the origin of the universe), then God must have created it.
P2 Science can't explain the origin of the universe.
C God must have created the universe.