APHI 221 – Mrs AC Austin
Different forms of Inductive Reasoning – Generalisations, Analogies and Reasoning from General Principles
Let’s begin by reviewing what we have covered in the last couple of lectures
What is an argument?
We know that an argument is made to address a specific problem, by offering a position and providing reasons for that position. By definition an argument requires reasoning.
If someone makes an argument they are making an appeal to REASON. To make an argument you must be able to say – to support my conclusion I offer you reasons to support my conclusion.
Your reasons can be evaluated for their TRUTH or ACCEPTABILITY.
Your reasons can also be evaluated based on the RELEVANCE to the issue and whether they are SUFFICIENT.
So in order to make an argument:
1. Your reasons should support a conclusion
2. There should be a relationship between reasons and a conclusion
3. There must be a connection between reasons and a conclusion
We have also learned that there are two common ways of making arguments – You can make a DEDUCTIVE ARGUMENT or you can make an INDUCTIVE ARGUMENT
A Deductive Argument is a type of argument where if the premises are true and acceptable then the conclusion must be a true conclusion. Thus in a deductive argument the conclusion follows necessarily from the premises and inferences.
Deductive arguments can take the form of categorical syllogisms like the example below:
Ayanda is girl. All girls are females. Therefore Ayanda is a female.
A syllogism is a type of logical reasoning where the conclusion is deduced or derived from two linked premises.
Here’s another example: An apple is a fruit. All fruit is good. Therefore apples are good.
An Inductive argument is a type of argument where the strength or weakness of the conclusion is dependent on the strength of the premises. An Inductive argument works by gathering support in its premises leading to a probabilistic conclusion. Thus in an inductive argument in an inductive, the premises are intended only to be so strong that, if they are true, then it is unlikely that the conclusion is false.
Inductive Arguments usually take the form of conditional or causal reasoning. For example here below:
A pink flamingo was observed at the Small Craft Harbour, a pink flamingo was observed at the Durban Harbour, pink flamingo was observed at Walvis Bay in Namibia, a pink flamingo was observed at Fish Hoek in the Cape. If all flamingos observed are pink then we can say with a degree of high probability that all flamingos are pink.
Causal Reasoning is a form of Inductive argument reasoning that allow us to determine which causes are most likely to be the reason behind an effect. A cause is something that brings an effect into existence. An effect is the result of something.
Today we will be looking into more detail at three forms of Inductive arguments – Genrealisations, Analogies, and Reasonging from General Principles. In these 3 types of Inductive arguments, we are asked to accept a conclusion because the situation, problem or issue is similar to another situation, problem or issue that we already know something about.
The first of these 3 forms of Inductive Argument is Generalisations.
GENERALISATION- is where we draw conclusions from a whole category based on specific cases or examples that we have from that category. We take something we know in a specific instance and apply it, generalising it to a larger group.
Keep in mind though that generalisations do have the positive feature of helping us to form reasonable expectations about how people will react in certain situations, or what will happen in a certain situation.
For instance – surveys and experiments are practical types of generalisations. If we poll 600 people about whether we should stop selling guns on websites like Amazon or Ebay, and 90% of those polled say that we should stop selling guns on Amazon or Ebay, then we can extend that to statistic out of 6000 and 60 000 etc and say something like in a town of 60 000 people 54 000 would be opposed to guns being sold openly on Amazon or Ebay.
Generalisations are often employed in scientific research. For example a scientist may study a specific troupe of monkeys and their habits and social dynamics and generalise it to all monkeys.
Even though generalisation typically tell us what is likely to happen in general – there is still room for exception.
The extent to which we can apply generalisations ranges from “all the time” to “most of the time” or “often” all the way down to “sometimes. This is when we call the form of inductive generalisation weak. The argument suffers from Overgeneralisation.
Here are a few examples of arguments that lean on generalisation (take note that these may not be true or good inductive arguments from generalisation – but they are nonetheless examples of generalisations
- · Last week 4 of the accused standing trial for crimes related to violent hijackings told the judge that they were unable to pay for private lawyers as they could not afford it. From this we can infer that people who violently hijack other people are very poor.
- · According to the statistics on crime in South Africa – in most instances where white farmers and families were murdered on their farms, the perpetrators were black young men. From this we can infer that all black young men in South Africa want to murder white farmers and their families.
- · Of the 19 hijackers on Sept 11, 2001, 15 were Saudi Arabian Nationals. I think we can safely conclude that Saudi Arabians are terrorists.
- · I have 4 Indian male friends ranging from 20 to 30 years old. All of them have Golf GTI’s. Don’t even bother trying to sell your Subaru to Priyesh, Indian men only buy Golf GTI’s.
- · I knew this guy who was a beggar. He was capable of doing work and getting paid for it just like me, but he was irresponsible and lazy and spent all his time drunk. Don’t give your hard earned money to any beggars on the street. They will spend all your heard earned money on alcohol.
- In South Africa, many government officials have been exposed as corrupt officials who have used public money to enrich themselves personally. From that we can say that all South African politicians are corrupt crooks, thieves and liars.
ANALOGIES
Analogies are good ways for us to think about what might happen in a new situation based on what happened in a similar one that we have some knowledge about.
So an analogy is when you make an example of something that is similar enough to something to make a comparison. You are able to see the similarities between the two and then transfer your understanding of the earlier thing that you know something about to the new similar thing that is new.
John is like a rock. - the comparison here is between a rock (something we have some understading about - the properties of rocks are that they strong, solid, steadfast) and John so(Something/somecsomen we dont know about He is strong, solid and steadfast.
Arguing by analogy means that if you say “A is similar to B, then if X is true for A, then X is also true for B. For example – A cricket ball is round and it rolls, a soccer ball is also round so it should also roll.
Another example of an analogy would be something like:
· Drug use is a matter of addiction and a breakdown in the impulse control mechanism in the brain. It's like overeating or alcoholism. It would be ridiculous to declare war on food or alcohol, so it's ridiculous to declare war on drugs.
Here is another famous analogy that Karl Marx wrote: “Religion is the opiate of masses.”
A Drug is something that makes people unmotivated, takes away their personal power and freedom and may ultimately kill them. Religion is analogous to a drug so the conclusion we draw (by similarity) is that Religion makes people apathetic and unmotivated and stops them from coming into their full power as themselves.
An Analogy’s strength is judged by how similar the examples being compared are. When you are presented with an argument by analogy you must closely examine the two situations being presented.
These are the questions you ask yourself to evaluate an analogical argument (inductive argument by analogy)
·
How are they similar?
· How are they not similar?
· How important are these differences?
An important thing to note is that all analogies are imperfect. The whole idea is that you are comparing two situations are not identical but fairly similar. Your job is to figure out whether they are sufficiently similar.
It is an error in reasoning when a person relies on a weak or false analogy. An analogy where the two cases are similar only in a few ways is a weak one. It may not be strictly speaking wrong but it is not strong enough support for the conclusion
· Maria does not enjoy the taste of lettuce. So Maria thinks she will not enjoy the taste of spinach either because they are both healthy and both are used to make a salad.
A false analogy is one which none of the important or relevant features are similar. Although the two cases may be similar in other ways that aren’t relevant to the issue. For example:
· Soccer and Cricket are both played with balls – so if you’re good at soccer you would be good at cricket.
Note here that that being good at a sport has nothing to do with the tools or equipment needed to play that sport.
When you are trying to evaluate strong or weak Analogous arguments, you can ask yourself the following questions:
· are the similarities relevant to the conclusion being made
· are the differences significant enough to undermine the analogy
EXERCISE:
Here are some more examples of analogous Inductive Arguments – evaluate them to be strong or weak arguments from an Analogy – if you think they are weak – explain why with reference to similarity and relevance of premises and conclusions. (take note that the inductive arguments made here do not necessarily reflect the opinion of the compiler of these common analogies)
· Since the world is similar to a clock in respect to its orderly design, and a clock has a maer, the world must also have a maker
· In the natural word, in order for a species to survive, its members have to reproduce. In most species there is a male and female and their coupling leads to reproduction. We are natural too – therefore homosexuality is ethically and morally wrong.
· Europa is a moon of Planet Jupiter. Europa has an atmosphere. The earth has an atmosphere. There is biological life forms on earth. Since there is life on earth there must be life on Europa.
· We should not blame the media for deteriorating moral standards. Newspapers and TV are like weather reporters who report the facts. We do not blame weather reports for telling us that the weather is bad.
REASONING FROM GENERAL PRINCIPLES
An Argument made when you are reasoning from general principles is the opposite of generalisations. In generalisations – you move from knowing things about a specific or few specific cases to a larger or general unspecific group.
Reasoning from general principles however, involves applying general principles to a specific case.
An argument from general principle takes something that is true or held to be true about the whole and applies it to a specific case that is determined to fall within the category of the whole.
For example: Most Conservative Christian folk in South Africa have indicated support a legislation that would criminalise abortion. Therefore if one had to run a poll asking people whether we should criminalise abortion, in typically Christian provinces like the Western Cape - where Sibongile a strong Christian lives, will vote to imprison women who choose to have abortions.
The strength of an argument based on the application of a general principle depends on how acceptable the principle is. In addition – the strength of the argument is also based on the degree to which the specific case fits into the category, covered by the principle.
For example:
Many people hold the general view that taxi drivers disregard traffic regulations.
That in itself should be fine, but see what happens if you make the following argument.
Since it is generally observed that all taxi drivers disregard traffic regulations, then Mbuyiseni who is a taxi-driver, must be a reckless, traffic law violating driver.
When a general principle is applied to a specific case that does not fit then the author has made an error in incorrectly applying the argument from general principles.
