# Inductive and deductive notes

Topics: Logic, Argumentative, Soundness Pages: 3 (439 words) Published: November 21, 2013
Philosophy notes 9-17-13
Two forms of argument
1) Deductive= provides logically conclusive spport for the conclusion Valid-if the premises are true then the conclusion cannot be false Invalid- it fail to provide support
Sound-the argument is valid and the premises are all true
Unsound- an argument with true premises that lead to a false conclusion 2) Inductive-provides probable support for the conclusion
Strong-premises are true conclusion is probably true
cogent-premises are true argument is strong
Weak-in adequateuncogent -premises are not true

Four steps for judging arguments
1) Find conclusion and premises
2) Ask: does the conclusion have to be true if the premises are true? Yes: valid=question: is it a sound argument
No: proceed
3) Is the conclusion probably true? Given the premises are true Yes:=strong question=cogent?
No: proceed
4) Does the argument fail to provide conclusive or probable support?

Guidelines
1) Assume argument is deductive or inductive if it looks so. 2) Note the indicator words
Test for consistency: would you judge someone or something you dislike the same way you would judge someone/thing you like?

Argument patterns
Pattern – content
Variables
Syllogisms=deductive argument made of three statements
Two premises (may have more)and one conclusion(always)
Conditional=if then structure
Antecedent =the statement that follows if
Consequent =statement that follows then
Modus ponens=affirming the antecedent﻿Philosophy notes 9-17-13 Two forms of argument
1) Deductive= provides logically conclusive spport for the conclusion Valid-if the premises are true then the conclusion cannot be false Invalid- it fail to provide support
Sound-the argument is valid and the premises are all true
Unsound- an argument with true premises that lead to a false conclusion 2) Inductive-provides probable support for the conclusion
Strong-premises are true conclusion is probably true
cogent-premises are true argument is strong...