Value Conflicts and
Assumptions
•Visible stated reasons
•Hidden/unstated ideas –
assumptions
Assumptions
•
•
•
•
Unstated
Taken for granted
Influential in determining the conclusion
Potentially deceptive
Look for reasons
• To support conclusion
• Necessary for reason to be true
• Value Conflicts – differing values that stem
from different frames of reference
• Value assumption – taken-for-granted
belief about the relative desirability of
certain competing values
Arguments Analysis
• Focus on the connections between the
arguments and the conclusion.
• Well-formed arguments
Validity
• Valid – if and only if it is impossible for the
premises of the argument all to be true
and the conclusion to be false
• Valid – if and only if all the premises of the
argument are all true then the conclusion
is true as well
• Boris is a student at State U
• All students at State U played football
________________________________
• Boris played football
•
•
•
•
x is an A
All As are Bs
___________
X is a B
• Either my daughter is on the phone or my
wife is on the phone
• It is not the case than my daughter is on
the phone
• _______________________________
• My wife is on the phone
•
•
•
•
Either P or Q
~P
___________
Q
• Argument by Elimination
•
•
•
•
•
Conjunction
P
Q
________
P and Q
•
•
•
•
•
Conjunction A and B
Disjunction A or B
Negation ~A
Conditional If A then B
Biconditional A if and only if B
(If A then B, and if B then A)