Chapter Two:Good Reasoning

Applying Ethics: A Text with Readings (10th ed.)Julie C. Van Camp, Jeffrey Olen, Vincent BarryCengage Learning/Wadsworth

Arguments

Premises, reasons, evidence, supporting statements, grounds, conclusion

Purpose

– To show that the conclusion is true OR

– To show that it is reasonable to accept the conclusion as true

Deductive Arguments

Arguments that claim to follow truth-preserving rules

Truth-preserving rule: if the first two statements (premises) are true, the conclusion will be true

Example of a truth-preserving rule:– If A, then B.– A.– Therefore, B.

How to disprove?– Counterexample

Inductive Arguments

An argument in which supporting statements, or evidence, aim to show that it is reasonable to accept that the conclusion is true

Warranted argument: a good inductive argument

Argue from individual examples to a general claim or generalization

What is a fallacy?

Fallacy: an unreliable means of arguing, one that does not provide good reason for accepting the argument’s conclusion

Formal fallacy: invalid deductive rules

Informal fallacy: various unreliable strategies that people tend to use

– Hidden premises that are false or irrelevant or otherwise suspect

Examples of Informal Fallacies

Ad Hominem Argument– An attack on the opponent rather than the

opponent’s argument

Faulty Analogy– Misuse of argument by analogy (an argument that

two things alike in some respects must be alike in other respects)

Questionable Authority– Supporting a conclusion by relying on the judgment

of someone who is not a reliable authority

More informal fallacies

Begging the question– Assuming a premise you want to prove

Equivocation– Implicit reliance on two different meanings of the

same word to reach a conclusion

Hand Waving– Claiming something is true (or false) because

everyone knows it

More informal fallacies

Hasty generalization– Reaching a general conclusion form a sample

that is biased or too small Appeal to ignorance

– Arguing that a claim is true (or false) because we have no evidence proving otherwise

Post Hoc Ergo Propter Hoc– “after this, therefore because of this”– Claiming that one thing is caused by another

because it follows the other

More informal fallacies

Red Herring– An irrelevant issue introduced to distract attention

from the issue at hand Slippery Slope

– Assuming an action will inevitably lead to an unwanted outcome as a result of the small steps that inevitably will follow

Straw Man– A distortion of an opponent’s actual position to

make it easier to attach