ARGUMENT BY ANALOGY.

       INTRODUCTION

   Argument is one of those things we do in our everyday life. Sometimes we do it consciously, some other times, we do it unconsciously. We argue most times to prove our point or refute other peoples point.

   Argument in our everyday life is what we do in a shallow way; but here we are going to look into argument in the real sense of it. We will look deeply into it and analyze in details what argument is all about.

   Here we are presented with the question of what argument by analogy is, and the problems of argument by analogy. In attempting to discuss in detail the question set before us, we will be looking into the following;

·         Argument:

                              Conclusion

                                 Premises

·         Inductive Argument

·         Deductive Argument

·         Fallacy:

                                 Some forms of argument under fallacy

·         Argument By Analogy:

                                  Structure of argument by analogy

                                  Positive, negative and neutral analogy

                                  Criteria for evaluating analogical argument

                                  Practical criteria for evaluating analogical argument 

                                  Strength and weakness of argument by analogy etc

                                  False analogy

·         Problems Of Argument By Analogy

    1In philosophy, an argument is a set of claims, one of which is supposed to be supported by the others. There are two types of claims in an argument. The first type of claim is the conclusion. This is the claim that is supposed to be supported by the premises. A single argument has one and only one conclusion, although the conclusion of one argument can be used as a premise in another argument (thus forming an extended argument). To find the conclusion of an argument, ask yourself “what is the point being made here?” If there is no point, then there is no conclusion and hence no argument.

1 Created and maintained by jim.pryor@nyu.edu, http;aphilosopher.wordpress.com/2008/02/14/definition-of-argument/

2The second type of claim is the premise. A premise is a claim given as evidence or a reason for accepting the conclusion. Aside from practical concerns, there is no limit to the number of premises in a single argument. To find the premise or premises of an argument, ask “what evidence is given for the point?” If there is no evidence, there are no premises and hence there is no argument.

     3Arguments can have unstated premises and even an unstated conclusion. However, to actually be an argument requires that enough is provided so that a person can recognize the argument as being an argument.

Varieties

     4There are two main categories of arguments, three if bad arguments are considered a category. The first type is the inductive arguments. The second type is the deductive argument. The third “type” of argument is the fallacy .

INDUCTIVE ARGUMENT

     5An inductive argument is an argument in which the premises are intended to provide some degree of support but less than complete support for the conclusion.Inductive logic deals with cases such as these; it is not concerned with the rules for correct reasoning in the sense of “valid”, or conclusive reasoning ; but rather , it is concerned with the soundness of those inference for which the evidence is not conclusive.

     6Inductive argument can also be said to be an argument which lacks claim of conclusiveness from the premises. In an inductive argument, the premises provides partial support for the conclusion. Even if the premises of an inductive argument are true; they do not support the conclusion with certainty.

Examples

Inductive Argument

     Premise 1: When exposed to the nerve argent known as “Rage”, the chimpanzees showed a massive                                                                     increase in aggression.
     Premise 2: Humans are very similar to chimpanzees.
     Conclusion: If exposed to “Rage”, humans would show a massive increase in aggression.7

     2,3,4, and 7 Created and maintained by jim.pryor@nyu.edu, http;aphilosopher.wordpress.com/2008/02/14/definition-of-argument/

        5  Philosophy made simple (page 237 239) by Richard h popkin ph.d ,and avrum stroll, ph.d

       6 Mr. Adebayo Ogungure

Premise 1: Most charistmatic members see visions

     Premise 2: Emma is a charistmatic member

     Conclusion: Emma sees visions

DEDUCTIVE ARGUMENT

     8A deductive argument is an argument in which the premises are intended to provide complete support for the conclusion.

     It deals with reasoning that tends to establish conclusive inference. To say that an inference is “conclusive”, means that if reasons giving are true then, it will be impossible for the inference based on the reasons to be false. Such reasonings are called “valid” reasoning. Deductive logic is thus concerned with the rules for determining when argument is valid.

     9A deductive argument can also be said as one whose premises are claimed to provide conclusive grounds for the truth of its conclusion. Every deductive argument is either valid or invalid. Valid if it is impossible for its premises to be true without its conclusion being true also, and invalid if other wise. Example of a valid deductive argument;

Examples

Deductive Argument

     Premise 1: If pornography has a detrimental effect on one’s character, it would be best to avoid it.
     Premise 2: Pornography has a detrimental effect on one’s character.
     Conclusion: It would be best to avoid pornography.10

  

     Premise 1: All Nigerians are Africans

     Premise 2: All Africans are coloured

     Conclusion: All Nigerians are coloured

8 and 10 Created and maintained by jim.pryor@nyu.edu, http;aphilosopher.wordpress.com/2008/02/14/definition-of-argument/

9 introduction to logic by irving copi and carl cohen(page 206)

Fallacy

   11An argument whose premises do not support its conclusion is one whose conclusion could be false even if all its premises were true. In cases of this kind the reasoning is bad, and the argument is said to be fallacious. We will discuss briefly, some fallacious arguments

The Argument From Ignorance: Argument Ad Ignorantiam

   12The argument from ignorance is the mistake that is commited when it is argued that a proposition is true simply on the basis that it has not been proved false, or that it is false because it has not been proved true.  We realise,on reflection,that  many false proposition has not yet been proved false,and many true proposition have not yet been proved true- and thus our ignorance of how to prove or disprove a proposition does not establish either truth or falsehood.(page 116)

The Argument To Inapproprite Authority: argument ad verecundiam

   13 The Fallacy Ad Verecundiam arises when the appeal is made to parties having no legitimate claim over the matter at hand. Its just like holding firmly on what a carpenter said about human bod..(page118)

Argument Ad Hominem

   14The phrase ad hominem translates into “against the person.” It names a fallacious attack in which the thrust is directed, not at the conclusion,but at the person who asserts or defends it.(page 122)

The Appeal To Emotion: argument ad populum

   15Here the premises are plainly not relevant to the conclusion and are delibrately chosen as instrument with which to manipulate the beliefs of the listener or reader.

   The argument ad populum, the appeal to emotion,is the device of every propagandist and every demagogue. It replaces the laborious task of presenting evidence and rational argument with expressive language and other device calculated to excite enthusiasm ,excitement, anger or hate.(page128)

 The Appeal To Pity: argument ad miserecordiam

16The appeal to pity may be viewed as a special case of appeal to emotion,in which the altruism and mercy of the audience are the special emotions appealed to.(page 129)

11-17 introduction to logic by irving copi and carl cohen(page 206)

The Appeal To Force: argument ad baculum

17This is the use or threat  of “strong arm methods” sometimes as a last  resort as a useful expedient when evidence or rational methods fail.(130)

Example of a Fallacy

Premise 1: Dave supports the tax reduction for businesses and says it will be good for everyone, but he owns a business.
Conclusion: Dave must be wrong about the tax reduction.18

             Argument By Analogy

     19An analogy is a comparison between two objects, or systems of objects that highlights respects in which they are thought to be similar. Analogical reasoning is any type of thinking that relies upon an analogy. An analogical argument is an explicit representation of a form of analogical reasoning that cites accepted similarities between two systems to support the conclusion that some further similarity exists. In general (but not always), such arguments belong in the category of inductive reasoning, since their conclusions do not follow with certainty but are only supported with varying degrees of strength. Here, ‘inductive reasoning’ is used in a broad sense that includes all inferential processes that “expand knowledge in the face of uncertainty” (Holland et al. 1986: 1), including abductive inference.

     20Argument from analogy is a special type of inductive argument, whereby perceived similarities are used as a basis to infer some further similarity that has yet to be observed. Analogical reasoning is one of the most common methods by which human beings attempt to understand the world and make decisions. When a person has a bad experience with a product and decides not to buy anything further from the producer, this is often a case of analogical reasoning.

Structure

     21The process of analogical inference involves noting the shared properties of two or more things, and from this basis inferring that they also share some further property. The structure or form may be generalized like so:

P and Q are similar in respect to properties a, b, and c.

P has been observed to have further property x.

Therefore, Q probably has property x also.

18 by Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/reasoning-analogy

                20 and 21http://en.wikipedia.org/wiki/Argument_from_analogy

     Of course, the argument doesn't assert that the two things are identical, only that they are similar. The argument may provide us with good evidence for the conclusion, but the conclusion does not follow as a matter of logical necessity. Determining the strength of the argument requires that we take into consideration more than just the form: the content must also come under scrutiny.

Example

     22Thus, we may observe a very great similitude between this earth which we inhabit, and Mars. Mars revolve round the sun as the earth does, although at different distances, and in different periods. mars borrow all its light from the sun, as the earth does. Mars revolve round its axes like the earth, and, by that means, must have a like succession of day and night. Mars have moon, that serve to give it light in the absence of the sun, as our moon does to us. Mars is in its motions, subject to the same law of gravitation as the earth is. From all this similitude, it is not unreasonable to think, that mars, like our earth, be the habitation of various orders of living creatures. There is some probability in this conclusion from analogy.

     23We can improve on this preliminary characterization of the argument from analogy by introducing the tabular representation found in Hesse (1966). We place corresponding objects, properties, relations and propositions side-by-side in a table of two columns, one for each domain. For instance, Reid's argument (Example 2) can be represented as follows (using ⇒ for the analogical inference):

↑	Earth (S)		Mars (T)
vertical	Known similarities:
	orbits the sun	← horizontal →	orbits the sun
	has a moon		has moons
	revolves on axis		revolves on axis
	subject to gravity		subject to gravity
	Inferred similarity:
↓	supports life	⇒	may support life

22 source forgotten ,23 by Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/reasoning-analogy

     Reid here constructs an argument to show the likelihood that Mars, is inhabited by living creatures. His argument boils down to this:

• Premise 1: The Earth is similar to Mars.
• Premise 2: The Earth is inhabited by living creatures.
• Conclusion: Therefore Mars is inhabited by living creatures.

So arguments from analogy have the following form:

• Premise 1. Generally, X is similar to Y
• Premise 2. A is true (or false) of X
• Conclusion. Therefore A is true (or false) of Y

     Arguments from analogy are generally considered to be a form of induction. They extrapolate from the known to the unknown. As they are inductive in nature, arguments from analogy do not have conclusions which are guaranteed by the premises. Rather, the conclusions of analogical arguments are at best probable, i.e. they provide rational grounds for believing the conclusion to be true.
 

We have positive negative and neutral analogies

     Positive analogies are those features which are known or thought to be shared by both systems, negative analogies are those features which are known or thought to be present in one system but absent in the other, and neutral analogies are those features whose status as positive or negative analogies is uncertain at present.24

25Criteria for evaluating analogical arguments

Commonsense guidelines

Logicians and philosophers of science have identified ‘textbook-style’ general guidelines for evaluating analogical arguments (Mill 1843/1930; Keynes 1921; Robinson 1930; Stebbing 1933; Copi and Cohen 2005; Moore and Parker 1998; Woods, Irvine, and Walton 2004). Here are some of the most important ones:

(1)The more similarities (between two domains), the stronger the analogy.

24 by Mary Hesse, http://en.wikipedia.org/wiki/Mary_Hesse

25 by Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/reasoning-analogy

(2)The more differences, the weaker the analogy.

(3)The greater the extent of our ignorance about the two domains, the weaker the analogy

(4)The weaker the conclusion, the more plausible the analogy.

(5)Analogies involving causal relations are more plausible than those not involving causal relations.

(6)Structural analogies are stronger than those based on superficial similarities.

(7)The relevance of the similarities and differences to the conclusion (i.e., to the hypothetical analogy) must be taken into account.

(8)Multiple analogies supporting the same conclusion make the argument stronger.

Practical Evaluation Of Argument By Analogy[26]

Suppose, for example, that I am thinking about buying a new car. I'm very likely to speak with other people who have recently bought new cars, noting their experiences with various makes, models, and dealers. If I discover that three of my friends have recently bought Geo Prizms from Burg and that all three have been delighted with their purchases, then I will conclude by analogy that if I buy a Geo Prizm from Burg, I will be delighted, too.

Evaluating Analogies

Of course, this argument is not deductively valid; it is always possible that my new car may turn out to be an exception. But there are several considerations that clearly matter in determining the relative strength or weakness of my inductive inference:

1.      Number of instances. If five friends instead of three report their satisfaction with the model I intend to buy, that tends to make it even more likely that I will be satisfied, too. In general, more instances strengthen an analogy; fewer weaken it.

2.      Instance variety. If my three friends bought their Prizms from three different dealers but were all delighted, then my conclusion is somewhat more likely to be true, no matter where I decide to buy mine. In general, the more variety there is among the instances, the stronger the analogical argument becomes.

3.      Number of similarities. If my new purchase is not only the same make and model from the same dealer but also has the same engine, then my conclusion is more likely to be true. In general, the more similarities there are between the instances and my conclusion, the better for the analogical argument.

4.       Relevance. Of course, the criteria we're considering apply only if the matters with which they are concerned are relevant to the argument. Ordinarily, for example, we would assume that the day of the week on which a car was purchased is irrelevant to a buyer's satisfaction with it. But relevance is not something about which we can be terribly precise; it is always possible in principle to tell a story in the context of which anything may turn out to be relevant. So we just have to use our best judgment in deciding whether or not some respect deserves to be considered.

                     26] by Garth Kemerling, http://www.philosophypages.com/lg/e13.htm

5.      Number of dissimilarities. If my friends all bought Geos with automatic transmissions and I plan to buy a Geo with a standard transmission, then the conclusion that I will be delighted with my purchase is a little less likely to be true. In general, the fewer dissimilarities between instances and conclusion, the better an analogical argument is.

         6.   Modesty of conclusion. If all three of my friends were delighted with their auto purchases but I conclude only that I will be satisfied with mine, then this relatively modest conclusion is more likely to be true. In general, arguments by analogy are improved when their conclusions are modest with respect to their premises

Analyzing arguments from analogy[27]

Strength of an analogy

     Several factors affect the strength of the argument from analogy:

• The relevance (positive or negative) of the known similarities to the similarity inferred in the conclusion.
• The degree of relevant similarity (or dissimilarity) between the two objects. The amount and variety of instances that form the basis of the analogy. Counterarguments

     Arguments from analogy may be attacked by use of disanalogy, counteranalogy, and by pointing out unintended consequences of an analogy. In order to understand how one might go about analyzing an argument from analogy, consider the teleological argument and the criticisms of this argument put forward by the philosopher David Hume.

     According to the analogical reasoning in the teleological argument, it would be ridiculous to assume that a complex object such as a watch came about through some random process. Since we have no problem at all inferring that such objects must have had an intelligent designer who created it for some purpose, we ought to draw the same conclusion for another complex and apparently designed object: the universe.

      Hume argued that the universe and a watch have many relevant dissimilarities; for instance, the universe is often very disorderly and random. This is the strategy of "disanalogy": just as the amount and variety of relevant similarities between two objects strengthens an analogical conclusion, so do the amount and variety of relevant dissimilarities weaken it. Creating a "counteranalogy," Hume argued that some natural objects seem to have order and complexity --- snowflakes for example --- but are not the result of intelligent direction. Finally, Hume provides many possible "unintended consequences" of the argument; for instance, given that objects such as watches are often the result of the labor of groups of individuals, the reasoning employed by the teleological argument would seem to lend support to polytheism.

 [27] http://en.wikipedia.org/wiki/Argument_from_analogy

False analogy[28]

     A false analogy is a faulty instance of the argument from analogy.

     An argument from analogy is weakened if it is inadequate in any of the above respects. The term "false analogy" comes from the philosopher John Stuart Mill, who was one of the first individuals to engage in a detailed examination of analogical reasoning. One of Mill's examples involved an inference that some person is lazy from the observation that his or her sibling is lazy. According to Mill, sharing parents is not all that relevant to the property of laziness.

Examples

       Person A: "I think that people can have some affection for their cultural heritage."

       Person B: "You're just like Hitler!"

     In the above example, Person B has evaded a reasoned discussion by tarring Person A with an irrelevant association to an idea that Hitler used. Of course no one person is identical to another to the extent that their proposals can be disparaged by a mere reference to that other person. It is a form of ad hominem: Attacking the messenger, rather than the message. The above example is also an example of Reductio ad Hitlerum and, in an online context, invokes Godwin's law

                     PROBLEMS OF ARGUMENT BY ANALOGY

     Truthfulness of the premises: if a premise of an analogy is false or not acceptable, it makes the   inferred conclusion unacceptable

     Number of similarities: for analogy to be strong in an argument, it really needs a good number of similarities.

     Relevance of similarities to the infered conclusion: analogy may have beautiful and nice similarities, but once it is not relevant to the conclusion, it renders the analogy useless

[28] http://en.wikipedia.org/wiki/Argument_from_analogy

                                   

                                   `BIBLIOGRAPHY

Philosophy Made Simple 2^nd Edition,  By Richard H Popkin Ph.D ,And Avrum Stroll, Ph.D

ISBN 0-385-42533-3

Introduction To Logic 9^th Edition By Irving Copi And Carl Cohen.

Isbn 0-02-325041-0

http;aphilosopher.wordpress.com/2008/02/14/definition-of-argument/

http://www.philosophypages.com/lg/e13.htm

http://en.wikipedia.org/wiki/Argument_from_analogy

http://plato.stanford.edu/entries/reasoning-analogy/

http://en.wikipedia.org/wiki/Mary_Hesse