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Techniques of Argumentation(Lecture 16: Reasons, opinions, and authority)

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When claims conflict

Aristotle: Opposite assertions cannot be true at the sametime

Law of Non-Contradiction: No proposition may besimultaneously true and false.

When faced with the conflicting claims pand Not-phowought one proceed?

Weigh the evidence and reasons supporting the claims

It is rational to believe a proposition only if there is goodreason to.

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Thats just your opinion

What is an opinion?

Plato distinguished doxa from episteme Belief and Knowledge

Certain beliefs amount to knowledge beliefs that are true beliefs that are based on good reasons (justification)

An opinion is a belief they are either true or false they are either based on good reasons or not

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Opinions and entitlements

Everyones entitled to their own opinion entitled to think whatever you like entitled to think whatever you like free of criticism entitled to have your views taken seriously

Youre rationally entitled to believe only what there isgood reason to believe

Many opinions are not supported by the evidence; and

many are false All opinions were not created equal!

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A matter of opinion

Thats a matter of opinion opinions differ on the matter many different opinions on the issue there is no fact of the matter

Licorice is tasty Its tasty to you but not to me You like it but I dont The issue is entirely subjective

Cant really disagree and argue over such issues

Dont confuse reason governed opinions with arationalsubjective tastes

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Appeal to authority

Appeals to authority can go wrong

Just because someone is a expert in one subject it doesntmake them an expert on every subject.

Einstein advocated for a vegetarian diet A PhD in Mathematics writes a self-help book The pope on evolution

Just because someone is well-known and on TV it doesntmake them an authority

Tom Cruise on psychiatry Celebrity endorsements of politicians

Religious, cultural, and social leaders often haveleaderships roles, but this authority should not be

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Authority and the Web

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Web sources

Authority

Who wrote it? What are their credentials?

Purpose

Why did they write it? What standpoint are they pushing?

Bias

What biases might the author have? What conflicts of interest? Who funds the website?

Support

Does the author provide good reasons? Cite credible sources?

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The whole problem with the world is that fools andfanatics are always so certain of themselves, but wiser

people so full of doubts -(Bertrand Russell)

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