#logicandreasoning

Rhetoric is a form of persuasive expression, tries to persuade reader or listener to accept particular beliefs by appealing and manipulate to emotions with words and techniques.

Explanation is a belief that doesn’t link a reason to a belief but rather than using a logical connection, uses a causal connection between premise and conclusion

Conditional are statements that consist of an antecedent and a consequent, “if… then…” e.g. If it’s over 38 degrees then the football match will be cancelled

To identify premises - Accept those that appear to be clearly implied by the arguer - Are necessary for the argument to work

Inference indicators similar to conclusion indicator are words/phrases which introduce or frame the premises and conclusions and which operate like signals, alerting the reader/listener to the location of the premises and conclusion in the argument.

Premise indicator indicate a premise “since…, because…, for…” Conclusion indicator indicates a conclusion “therefore…, hence…, thus…”

STANDARD FORM steps of putting an argument into standard form: 1. Identify the argument’s conclusion and then it’s premises - distinguish between what belongs to the argument and what is simply ‘window dressing’ 2. Find a way to express its parts as clearly and precisely as possible which remaining faithful to the arguers apparent intentions - May be hard to do if the proposition is >Ambiguous: have more than one possible interpretation in a given context >Vague: meaning of word is uncertain - To deal with this, employ: 2a. Principle of charity which states that, when attempting to reconstruct an argument, you should choose the best possible representation of that argument.  - Based on available evidence, and starting from the pre-supposition that the arguer is attempting to produce the best possible argument for their position. 2b. Remove all indicators and express proposition in plain and simple language. Meaning should be accurate and proposition should be articulated to produce the maximum degree of clarity. 3. Place into the standard form format P1 xx P2 xx therefore C

EXTENDED ARGUMENTS sub-arguments are arguments chained together to form a whole argument. They’re important because it enables and establishes whether or not we have good reason to accept the conclusion of the main argument.

Intermediate conclusions (CONCLUSIONS WHICH ARE ALSO PREMISES) P1 P2 C1 <-----conclusion which is also premise to final conclusion P3 C2

OTHER TOOLS FOR ARGUMENT Arguments to the best explanation are inductive arguments which commence with premises that describe particular facts and conclude with a hypothesis which, if true, would explain those facts. Best explanation for a given phenomenon e.g the laundry is not on the washing line. Patrick must have brought it in while I was out. To decide the best possible explanation: 1. Is the chosen explanation the least complicated? 2. Does the explanation cohere with what we already know? 3. Is the explanation comprehensive (explain more than other explanations could)? inductive arguments are when conclusions follow on from premises with probability rather than necessity

Reductio Ad absurdum is an argument technique where the arguer argues from a set of premises to the logical consequences of those premises to demonstrate the inaccuracy or absurdity of a particular position.

Transcendental arguments are often employed in response to scepticism.    e.g. “but how do we know?”

Analogies are used to make extended comparisons between things to make abstract or difficult concepts comprehensible. The link between the given concept make it more readily understood.                                                                                                                                                                                                                                                                                                                                                                                                                                                          Thought experiments are imagined scenarios or situations created by philosophers to test ideas, explore boundaries of concepts or examine the implications of theories. E.g. Brain in a vat, Chinese room. Are a tool to help readers engage with the essence of a problem and to think about it both critically and imaginatively.

Useful fictions are imagined objects or entities which philosophers create to help explain concepts or investigate the consequences of particular ways of being. Provides us with a tool to consider not only particular theories and their consequences, but the nature of the world and ourselves, why it and we are the way we are, and how both could be improved.

EVALUATING ARGUMENTS Purpose of evaluation is to decide whether or not there are sufficient grounds for accepting a particular conclusion. The relationship between the premises and conclusion can be faulty or at least one of the premises is false. Analogy of a receipt.

Logical assessment: validity and cogency are terms describing the relationship between an argument’s premises and its conclusion. A conclusion following a set of premises logically, is described as valid/cogent. Validity is a property of well-formed deductive arguments which are arguments where the conclusion is presented as following on the premises necessarily. E.g. “ All unmarried men are bachelors.” Validity is a judgement relating to the structure of an argument not to its content. Just because an arguer’s reasons for a belief are good, this is no guarantee that the conclusion they have arrived at should be accepted.         

An invalid argument can have true premises and a true/false conclusion or false premises and a true/false conclusion. The premises provide a good reason to expect that the conclusion is true rather than false.                      

Inductive generalisations are a form of inductive argument which generalise from a series of samples to a certain case. E.g. (P1) I am often tired when I get less than 5 hrs of sleep, (P2) Last night I got 5 hours of sleep therefore (C) I will be tired. They can appear as analogy, rule of thumb or arguments to best explanation

Cogency relates to inductive arguments .How well the premise supports the conclusion will determine if the argument is cogent or not. Cogency is a matter of degree (clearly cogent, weakly cogent or not cogent)

Inductively strong/ inductively forceful is when the premises strongly support the conclusion. An argument is inductively strong if, given no other information except for that which is contained in the premises, it would be more reasonable to expect that the conclusion is true rather than false.

Factual assessment: truth of the premises will be good grounds for accepting an argument .Truth is the property of statements thus only premises and conclusions can be described as true, never arguments. To assess whether a premise or conclusion is true or false: 1. Look at evidence that supports the belief expressed in the premise/conclusion 2. See what evidence there is against the belief. <- one way to do this is to look for a counter-example which are exceptions to generalisations used to challenge the truth of a generalising statement.  Some truths can be relative, that is to say, one truth may be false to someone but be true to another person. A non speaker-relative proposition is when the factual status of a proposition is independent of the speaker asserting it (e.g. Melbourne is the capital city of Victoria) Speaker relative propositions are propositions that expresses a preference or attitudes to the individual who asserts them. They are about the individual not the world.

Vagueness: occurs when the wording of a proposition makes it difficult to assess its precise meaning. (e.g. using the word “some”). An argument is sound if the premises are true and is valid/cogent. To be sound an argument cannot be ‘sort of’ or ‘kind of’ sound. It is either sound or unsound.

FURTHER TOOLS FOR EVALUATING ARGUMENTS        Rhetorical ploys are persuasive devices which masquerade as arguments appeal directly to emotions. Some include:

Trading on an equivocation is when the arguer uses a conceptually vague or ambiguous word phrase in an effort to influence our interpretation of a particular view.  e.g. Shop at Browning’s – the biggest name in hardware. ‘biggest’ is ambiguous because this can mean the biggest store or the biggest name  or the most renowned name. The statement may be true, but it may not be true in the way we think it is.

Trading on implicature is to hint at a proposition but not actually state it, thus avoiding responsibility for the reader’s interpretation.  e.g. According to a leading economist, the arrival of more asylum seekers into Australia would put a massive strain on the economy. People may interpret this as ‘there WILL be a strain on the economy because more asylum seekers are coming to Australia’ when, in reality, a hypothetical situation seems to be proposed. These implications attempt to arouse emotional responses which simultaneously making the reader believe that they’ve been presented with an argument for that response.

Value-Laden language is a means of shaping our perceptions, often with the intention of modifying our esteem for a person or thing. E.g. ‘ultimate originally means the final or last, but it is now lead to be mean something great or superior’

Smokescreening is the tactic of avoiding discussion of the issue at hand by addressing a side issue instead. E.g a boyfriend catches his girlfriend cheating on him by reading her text messages. She would be smokescreening if she launches into a speech about he has breached her privacy.

Appeals to novelty or popularity appeals to our fears, desires or egos. e.g. ‘We are now living in a post-feminist age, and as such, feminism is no longer relevant’ Being told that it is old fashioned is intended to incite us to give up our beliefs by appealing to our fear of being behind the times and our desire to see ourselves as intellectually current. Appeals to popularity works in the same way but targets a very particular set of desires. E.g. ‘Harvey denim jeans- the denim of choice for Melbourne’s hot young things.’ Appeals to desire to be a hot young thing and also makes us assume that this is surely something edgy and fashionable. The premise ‘the best jeans to purchase are the ones chosen by Melbourne’s hot young things’ is subjective.

Appeals to compassion intends to incite action by inviting us to empathise with the plight of others.  Images and slogans do not alone provide good reason for engaging in the encouraged action.

Scare tactics incite fear for the purposes of influencing behaviour, action or attitudes. E.g. If Australia pulls its troops from Iraq, our country will no longer be safe. No reason has been presented as to WHY troop withdrawal would make our country no longer safe. Scare tactics have no justified connection between the fear incited and the course of action recommended.

FALLACIES (poor reasoning) The two types of fallacies are: 1. Formal fallacies: that fault lies in the form or structure of the argument 2. Informal or substantive fallacies: fault lies in the arguments’ content. Common formal fallacies include:

Affirming the consequence occurs when an argument adheres to the following pattern If A then B, B therefore A. This is invalid because it is only stated that B is conditional to A and not A being conditional to B. P1 would give the conditional and if P2 meets those conditions it would be valid. A valid argument would be affirming the antecedent also known as modus ponens.

Denying the antecedent is when the fallacy occurs when we argue from the negative of the conditional’s antecedent to a conclusion in which the consequent is neglected. If A then B, Not A therefore not B. The conditions only state that B is conditional because of A but does not say that the lack of A causes the lack of B. This is also known as modus tollens.

Depriving ‘ought’ from ‘is’ This fallacy occurs when a prescriptive conclusion is deduced solely from descriptive premises. e.g. People should stop eating meat because it involves the killing of animals. This is invalid because the mere fact that the consumption of meat involves the killing of animals doesn’t in itself, provide sufficient grounds for concluding that we shouldn’t eat meat. A value cannot be derived purely from a fact.

Common informal/substantial fallacies include: Ad populum fallacy is committed when we apportion praise or blame to an argument or idea simply because it accords with the majority view. E.g. Polls have shown that over 80% of people disagree with the introduction of nuclear energy which indicates that it should not be introduced. This argument is unsound because the view of the majority of the population doesn’t in itself, provide good reason to accept or disregard an idea/argument.

Ad personam fallacy is when, rather than judging an argument on its own merits, we judge it according to how our response will make us feel. E.g. understanding the arguments for the legality of abortion but rejecting these because you may feel uncomfortable agreeing with consent of murder of a baby.

Ad hominem fallacy is usually committed in one of two ways: 1. A claim is rejected because of dislike or disapproval for the individual who makes it  2. The individual who presents the argument is attacked.

The genetic fallacy occurs when we mistakenly judge the veracity of a claim according to its origins. E.g. ‘Of course professor marks will argue that climate change exists. He used to be a left wing political activist back in his university days.’ This doesn’t prove that his old views make his argument wrong, it is merely an assumption.

The naturalistic fallacy is committed when an arguer attempts to prove an ethical claim by appealing to a definition of good in terms of one or several natural properties. Occurs when an arguer equates what is natural to what is right and what is unnatural to what is wrong. E.g. When we look to nature we see that it endorses the view that it is right that the strong should dominate the weak. The second premise does not give us sufficient reason to conclude it is right for the dominant to do so. This fallacy has a strong resemblance to the fallacy for deriving ‘ought’ from ‘is’. The difference is that the naturalistic fallacy specifically relies on appeals to nature to support conclusions.

The fallacy of conflating morality with legality When someone claims that something right/wrong based on the laws which are in favour of the idea. Just because something has no law for/against it doesn’t mean that it is immoral/moral thus pointing out that an action is in line with or against the law is not a sufficient reason for a conclusion.

Causal fallacies occur when we make incorrect inferences about the cause of something. They can be divided into 3 types: 1. Post hoc ergo prompter hoc which is committed when we infer that event A causes event B simply because event B followed event A. This is fallacious because it relies on a flawed assumption that the preceding event caused the following event 2. Mistaking correlation for cause occurs when it is assumed that a causal relationship exists between the two because one state of affairs is usually found in conjunction with another state of affairs. 3. Inverting cause and effect occurs when it is assumed that if A causes B, then an absence of A will precent B

OTHER PROBLEMS WITH ARGUMENTS (poor reasoning)

Begging the question is to assume, in one or more of the argument’s premises, the truth of what is to be proved by the conclusion. E.g. ‘we only have to look to the diversity and complexity of nature to know that God exists. Only god could bring about such diversity and complexity, thus we can be sure God exists. Arguer is claiming that God’s existence is proof of nature and that nature can be explained by god’s existence. Argument assumes that the truth of its conclusion in one of its premises. This is also known as circularity/ circular reasoning.

Slippery slope fallacy occurs when an arguer mistakenly assumes that a particular course of action will inevitably lead to certain undesired outcomes without supplying good reasons to suppose that these outcomes will indeed eventuate. E.g. if we ban gambling, we’ll start to ban arcade games, where will it stop? Argument provides no good reason for which the arcades being banned will be a consequence of banning gambling.

Straw man fallacy is akin to a dirty trick which is committed when an arguer criticises a caricaturised, distorted or simplified version of the position, thereby giving the false impression that the real argument has been defeated