Logical and Illogical Argument
Logical and Illogical Argument
You don’t write because you want to say something, you write because you have something to say.
– F. Scott Fitzgerald
Introduction
This lesson presents the principles of logical argument. Here you will learn how to construct convincing arguments that can persuade the skeptical reader.
A convincing argument consists of a series of claims that are supported by both evidence and a valid line of reasoning. A number of common fallacies are also analyzed, understanding of which will help you protect yourself from critical counter-arguments.
Claims, evidence and logical reasoning
Convincing arguments
Your solutions will only be accepted if you present a convincing argument in your EVALUATION slot. A convincing argument consists of claims which are supported by evidence linked by a valid line of reasoning. A well-argued report or proposal will consist of a sequence of claims and supporting evidence; together, these present a convincing case to support your final claim that a certain course of action is necessary—this is your recommendation or OUTCOME.
Claims
A claim is any statement not immediately provable by observation. It is any statement that must be argued for—and so can be argued against! Generalizations, predictions, evaluations, judgments, and recommendations are all claims in this sense.
A claim is a statement that you want your readers to believe.
Evidence
The evidence consists of established statements of fact. You must provide sufficient, reliable facts to support your claim. Once a claim has been established in this way, it can be used as evidence—as a fact—to support a further step in the argument.
Line of reasoning
But facts alone are not enough to support a claim. There must be a logical connection between the claim you make and the evidence you use to support it. Then the reader will accept that the evidence does, in fact, support the claim. This valid linking of claims and evidence is a logical argument.
Consider this invented example from a document arguing for the opening of new Off-Course Betting Centres (OCBCs) by the Hong Kong Jockey Club.
Example 1
We urge you to support the application for a license to open a new OCBC in Tsing Yi. OCBC clearly performs an important social function, allowing a legal opportunity for the community to engage in betting. In areas with comparable demographics, such as Tsuen Wan or Ma On Shan, the level of illegal gambling has consistently fallen following the opening of OCBCs.
Let us analyze the argument here. If we examine it closely, expanding points that seem to be presented implicitly, it looks something like this.
| EVIDENCE |
In Tsuen Wan and Ma On Shan, and other areas, the level of illegal gambling has consistently fallen following the opening of OCBCs. AND Tsing Yi has similar demographics to these areas. |
| LINE OF REASONING |
THEREFORE the level of illegal gambling in Tsing Yi will fall if an OCBC opens. ASSUMING THAT reducing the level of illegal gambling is good, THEN |
| CLAIM |
you should support this license application. |
Counter-arguments
This is quite a strong argument. It presents evidence and a line of reasoning to support its claim. Nevertheless, a skeptical reader on the District Board can bring powerful counter-arguments against it.
Counter-arguments attack either the evidence, the line of reasoning, or both.
The DB member may attack the evidence by saying:
There is no clear evidence that the level of illegal gambling falls when OCBCs open. The figures from the police are quite unreliable. We have no real idea of the scale of illegal gambling that goes on either before or after.
or
Tsing Yi is quite unlike Tsuen Wan and Ma On Shan. It has its own special characteristics. Your comparison is not justified.
Or the line of reasoning could be attacked:
Even if I accept your evidence, there is no reason to say that because this effect occurred in the past it will happen again.
The importance of value judgments
Notice the key role played in the argument by the value judgment:
Reducing the level of illegal gambling is good.
Most values of this kind are implicit and not stated overtly. They are assumed. They are, however, extremely important and have a critical effect on the success of your argument.
Brief check
If you can make a strong case to demonstrate that your ideas are in tune with the central values and strategic positioning of your organization, you stand a good chance of persuading senior managers of the worth of your ideas.
The following illustrates some common flaws in an argument. Awareness of these will enable you to argue your cases more convincingly—especially against skeptical readers!
“After this, therefore because of this”
Example
Shortfalls in training processes
- Over the past five years, the technological support to banking operations has become increasingly complex, demanding increasingly sophisticated operating and maintenance techniques. At the same time, our sources of skilled labor have decreased as the labor market has tightened. Consequently, we have had to rely increasingly on inefficient on-the-job training to bring staff up to levels of independent competence. Outdated training methods have resulted in a gradual slowdown in equipment installations, an increase in the number of requests for repairs, and a long waiting list for service calls.
Analysis
| EVIDENCE | Technological support to banking operations has become increasingly complex, demanding increasingly sophisticated operating and maintenance techniques,
AND sources of skilled labor have decreased as the labor market has tightened. |
| LINE OF REASONING | THEREFORE
we have had to rely increasingly on inefficient on-the-job training RESULTING IN |
| CLAIM | a gradual slowdown in equipment installations, an increase in the number of requests for repairs, and a long waiting list for service calls. |
This argument can be attacked because it claims that there is a chain of cause and effect from the labor market, through the training methods, to the service shortfalls. But these links are not supported by any evidence of how one affects the other.
The service shortfall could result from many other causes, such as weak administrative systems, poor purchasing policy, or insufficient remuneration packages to attract qualified staff.
Good practice
Don’t assume that because EVENT 1 preceded EVENT 2, then EVENT 1 caused EVENT 2. Explain the mechanisms underlying your cause-effect links.
False dichotomy
Example
Analysis of Technical Training Methods
- There are four basic training methods (see Annex A for detailed comparisons) ranging from established methods to new techniques:
- On-the-job training (OJT)
- Classroom instruction
- Programmed learning
- Multimedia training packages
Analysis
This is not so much poor reasoning, but poor classification. Here the writer presents four alternatives, but the critical reader can ask:
Are these the ONLY alternatives? Is this a comprehensive list? What about private study not through programmed learning?
Or:
Are these mutually exclusive? Can’t we use these in combination?
Good practice
When presenting alternatives, be explicit as to whether they are a comprehensive list of options. If not, explain why not. State whether options are mutually exclusive or can be used in combination.
Claims without evidence
Example
On-the-job training
- Every time we hire new technical support staff, or transfer staff from one unit to another, they are given OJT. This continues until they are fully able to perform their tasks independently. Although the method is effective in the long run, it is slow and inefficient.
Analysis
| EVIDENCE | ? |
| LINE OF REASONING | ? |
| CLAIM | Although on-the-job training is effective in the long run, it is slow and inefficient |
The claim here is not supported by any evidence or line of reasoning. It is just a judgment presented without any support.
In some cases, your credibility as a professional, as an expert in your field, may enable you to make unchallenged judgments of this kind. Again, seniority may give you the confidence to make pronouncements without the need for argument.
If you doubt your intrinsic credibility, however, you had better include some support for your claims!
Good practice
Never make a claim without supporting evidence unless you are certain that it will be accepted without question by your reader.
Evidence without claims
Example
Classroom instruction
- Specialist technical instructors can be hired at approximately $400-600 per hour for delivery of training to groups of 12-15 at a time. Preparation of training materials can be costed at a similar rate but expenses can be recouped by multiple deliveries of courses. Classroom instruction is frequently used for theoretical rather than for practical hands-on processes.
Analysis
| EVIDENCE | Specialist technical instructors cost $400-600 per hour
AND preparation of training materials costs the same AND expenses can be recouped by multiple deliveries of courses AND classroom instruction is used for theoretical rather than for practical training. |
| LINE OF REASONING | ? |
| CLAIM | ? |
This paragraph presents data but makes no use of it as evidence to support any claim. This is the “So what?” factor referred to on page 32.
Sometimes presenting a claim may be superfluous—you may want the evidence ‘to speak for itself. On other occasions, a subheading may adequately convey the claim you want to make. Generally speaking, however, reports and proposals benefit from explicit statements of position.
In general, don’t present evidence without a claim unless you are certain that your readers will draw the same conclusion from the data as you intend.
Good practice
Use data for its value as evidence to support a claim. Exclude data which is only interesting ‘for its own sake’ or ‘for the sake of completeness. The state claims explicitly.
False comparisons
Example
Programmed instruction
- Programmed instruction allows trainees to work at their own pace through specially designed materials and has been widely used for teaching routine tasks to individuals or groups. Bank of America report in Hong Kong Trainer July 1997, however, that while programmed learning led to a 35% savings in instructors’ salaries, trainee bank tellers were rapidly demotivated by the mechanical aspects of the method. This method is not likely to be effective for technical training in AsiaBank.
Analysis
| EVIDENCE | At Bank of America, programmed learning led to a 35% savings in instructors’ salaries
BUT trainee bank tellers were rapidly demotivated by the mechanical aspects of the method. |
| LINE OF REASONING | AND
[what happens in Bank Of America will also happen in AsiaBank] THEREFORE |
| CLAIM | This method is not likely to be effective for technical training in AsiaBank |
This argument relies on an implicit line of reasoning that assumes that training in Bank of America is comparable to training in AsiaBank, and that bank tellers react to training methods in similar ways to technical support staff. This may be true or it may be false, we have no evidence to judge. In any case, the critical reader can attack this argument based on a false comparison.
Good practice
If you base your arguments on a comparison, establish why the two conditions are similar before drawing conclusions.
Appeals to popularity and novelty
Example
Multimedia training packages
- Multimedia, in the form of video, CD-ROM, or computer-based training, is rapidly gaining popularity with training departments worldwide. It is generally well-received by trainees and is seen as the newest and most up-to-date approach to skills development.
Analysis
| EVIDENCE | Multimedia is increasing in popularity with trainers and trainees.
AND multimedia is the newest training method. |
| LINE OF REASONING | ASSUMING THAT
[what is popular is good] AND [what is new is good] THEREFORE |
| CLAIM | [we should adopt multimedia methods] |
Here again, we have evidence stated without explicit reasoning or claims. The implicit message is clear enough, though. Because multimedia is popular and new, we are supposed to conclude that we should adopt the method. This is only convincing if we accept the clearly false line of reasoning that popularity and novelty must always be pursued.
Good practice
Avoid appeals to popularity or novelty unless you can clearly demonstrate how these can contribute to achieving corporate aims.
Appeals to authority and tradition
Example
- The Association of Hong Kong Trainers in their latest bulletin described in-house CD-ROM production as “within the reach of any large corporation and with today’s mature technologies certainly the wave of the future in delivering in-house training.”
Analysis
| EVIDENCE | The Association of Hong Kong Trainers supports multimedia |
| LINE OF REASONING | ASSUMING THAT
[the Association knows what it’s talking about] THEREFORE |
| CLAIM | [we should adopt multimedia methods] |
This example, like the one before, also appeals to novelty but supports this with a further appeal to authority. Questioning the line of reasoning here involves questioning the power and authority of the Association of Hong Kong Trainers. This may not be difficult, but consider the difficulty of attacking similar appeals, for example:
This proposal is supported by the Director of —
IT has endorsed the technical feasibility of this plan.
The Board of Management has never had more than twelve members.
Such appeals to authority and tradition can be extremely effective.
Good practice
Use appeals to authority and tradition with great care—they invoke issues of power and influence that can be highly sensitive.
Appeals to shared values
Example
Conclusion
- AsiaBank has long been at the forefront of technical developments in operations and services. We should take this opportunity to move into the new field of multimedia training and gain the service advantages that will ensue.
Analysis
| EVIDENCE | Multimedia training is a new field
AND AsiaBank has a tradition of technical innovation AND multimedia training will improve service. |
| LINE OF REASONING | ASSUMING THAT
[adopting technical innovations is good] AND [improving service is good] THEN |
| CLAIM | we should adopt multimedia methods |
The previous two pages have dealt with appeals to specific values: popularity and novelty, and authority and tradition. In this conclusion, we have one appeal to the intrinsic value of innovation and another to the value of service quality. Such appeals will be effective if these values are shared between writer and reader. A reader who holds the same values is likely to read this conclusion and respond positively. The converse is also true.
Whether or not a reader holds certain values is not simply a matter of personal tastes and beliefs. It involves a whole complex of elements including cultural background, age, gender, profession, and position in the hierarchy.
Good practice
Be aware of your readers’ values. These will depend on personal beliefs, professional background, corporate status and position, and extent of identification with corporate values and strategic plans. Use these appeals with care.
Summary of good practice in logical argument
“After this, therefore because of this”
Don’t assume that because EVENT 1 preceded EVENT 2, then EVENT 1 caused EVENT 2. Explain the mechanisms underlying your cause-effect links.
False dichotomy
When presenting alternatives, be explicit as to whether they are a comprehensive list of options. If not, explain why not. State whether options are mutually exclusive or can be used in combination.
Claims without evidence
Never make a claim without supporting evidence unless you are certain that it will be accepted without question by your reader.
Evidence without claims
Use data for its value as evidence to support a claim. Exclude data that is only interesting ‘for its own sake’ or ‘for the sake of completeness. The state claims explicitly.
False comparisons
If you base your arguments on a comparison, establish why the two conditions are similar before drawing conclusions.
Appeals to popularity and novelty
Avoid appeals to popularity or novelty unless you can clearly demonstrate how these can contribute to achieving corporate aims.
Appeals to authority and tradition
Use appeals to authority and tradition with great care—they invoke issues of power and influence that can be highly sensitive.
Appeals to shared values
Be aware of your readers’ values. These will depend on personal beliefs, professional background, corporate status and position, and extent of identification with corporate values and strategic plans. Use these appeals with care.
