Arguments in Action

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Arguments in Action

A statement is a sentence with a truth value, so it can be true or false. A statement is not an exclamation, a question, a command, or an instruction. An argument is a collection of statements, including premises and a conclusion. It attempts to assert or deny something, with the premises leading to the conclusion. An argument is not an explanation or a summary. A hidden premise is an assumed or unstated premise that an argument relies on.

Valid Arguments

Valid arguments guarantee true conclusions when the premises are true. If one or more of the premises are false then they can have a false conclusion. Validity is how well structured an argument is, not whether its conclusion is true or not.

Invalid Arguments

Invalid arguments don't always guarantee true conclusions when premises are true. It is still possible for invalid arguments to have true premises and true conclusions. Invalidity describes how badly structured an argument is, not whether its conclusion is false or not.

Inductive Arguments

An inductive argument aims to reach a conclusion which will probably be true. Conclusions are drawn about a wider grouping from a small sample, i.e. the conclusion goes beyond what is contained in the premises, e.g. I have just seen 100 white swans, so the next swan I see will be white too.

they often use particular premises to prove universal conclusions

their conclusion goes beyond what is contained in their premises

they can yield a false conclusion even when their premises are true

they are therefore all technically invalid arguments and so unsound

their conclusions can only ever be probable, not certain

they can be strong or weak e.g. I have seen four elephants with big ears, so all elephants have big ears (weak); I have seen 50,000 elephants and they all had large ears (strong)

a cogent argument is strong and the premises are true. An inductive argument is therefore not cogent if either a premise is false, or if it is weak

Deductive Arguments

A deductive argument aims to reach a certain conclusion which will be true. It does not go beyond what is contained in the premises, e.g. all dogs are black, Rover is a god, so Rover must be black. It can either be true or false.

they often use universal premises to prove particular conclusions

their conclusion doesn't claim more than their premises

if valid, they can't yield a false conclusion when premises are true

they are therefore capable of being described as valid arguments

their conclusions are capable of being certain truths

Conductive Arguments

In conductive arguments the support for the conclusion is always convergent. Conductive arguments have premises which are independent of each other, which separately converge on a conclusion. In a cogent conductive argument, the premises must be positively relevant to the conclusion. In order to determine if the premises of a conductive argument adequately support their conclusion, we must collectively consider the premises' cumulative strength, putting this together with other evidence that might cunt against the conclusion. We have to consider whether negatively relevant points outweigh the positively relevant ones. This could be weighing up the pros and cons of a situation.

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Fallacies

A fallacy is a faulty argument. Fallacies can be faulty for a number of different reasons. Fallacies can be categorised as formal fallacies or informal fallacies.

formal fallacy - an argument with an invalid form

informal fallacy - might be formally valid but often has a dubious premise, so rendering it unsound

Formal Fallacies

denying the antecedent - any argument with the underlying invalid form:

P1: If P then Q

P2: Not P

C: Not Q

affirming the consequent - any argument with the underlying invalid form:

P1: If P then Q

P2: A

C: P

Informal

slippery slope - arguments which make increasingly unlikely claims to arrive at a radical conclusion from seemingly innocuous premises

P1: If P then Q

P2: If Q then R

P3: If R then S

C: If P then S

appeal to authority -arguments that try to support a proposition by pointing to some eminent source, appeal to authority is not a fallacy if the authority is an appropriate source

P1: If P then Q

P2: P

C: Q

appeal to emotion - instead of facts, persuasive language is used to develop the foundation of an appeal to emotion-based argument. Thus, the validity of the premises that establish such an argument doesn't prove to be verifiable

ad hominem - arguments that attack the person who is presenting a point of view rather than the view they support

abusive - when a personal slur is made on the arguer

circumstantial - where it is alleged that the arguer profits from their adopted position

tu quoque where it is alleged that the arguer doesn't practice what they preach

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Argument Evaluation

Acceptability

knowledge - a claim is known a priori to be true, can be accepted as common knowledge, represents facts relevant to the conclusion

plausibility of claims being made - a claim is plausible if it subjectively seems worthy of belief even if we have no necessarily studied its objective ground. A plausible claim can turn out to be false, and an implausible claim can turn out to be true

ambiguity - this means that different senses or references are associated with the word or expression, and that it is not clear from the given context which of these senses is meant. To say a statement is ambiguous means that the sentence is confusing in its whole meaning, although each word in it is clear, because of the grammatical structure among the words

lexical ambiguity - an ambiguous word e.g. the bank is beside the river. Equivocation is a type of this, particularly the same word is used with two different meanings, with the purpose of misleading the reader

grammatical ambiguity/syntactic ambiguity/amphiboly - the presence of two or more possible meanings withing a single sentence or sequence of words. Amphiboly is the grammar of the sentence e.g. I like chocolate cake better than you

confirmation bias - this is the tendency to search for, interpret, favour, and recall information in a way that confirms one's beliefs or hypotheses, while giving disproportionately less consideration to alternative possibilities. The effect is stronger for emotionally charged issues and for deeply entrenched beliefs. e.g. when investors have a love for a company maybe due to its products or CEO, it leads investors to overpay for investments that they want to make

appropriate appeal to authority - an argument may be acceptable if the appeal to authority is appropriate, e.g. the Met office say that it will rain tomorrow

Relevance

analogical arguments - an analogical argument is an argument in which on concludes that two things are alike in a certain respect because they are alike in other respects. Analogical arguments are often used in cases in which one thing (X) is accepted/seen as plausible and another (Y) is not, to get the audience to accept Y or see it as plausible. For example, a person might start with something everyone accepts, such as the fact that if a person has the blood cut off to her brain for too long, she'll suffer brain damage. The person could then make an analogy: the education system is like the "brain" of society and money is the blood of this brain. Finally, the person might conclude by claiming that cutting off money to the education system will damage society.

Premise 1: X has properties P, Q, and R.

Premise 2: Y has properties P, Q, and R

Premise 3: X has property Z as well.

Conclusion: Y has property Z

If an analogy is inappropriate then it renders the argument irrelevant