1. Disagreements, Claims, and Reasons
The term argument as used in critical thinking does not mean a quarrel between people. Rather, it is a structure of reasons given as proof of a claim. When we maintain a position we must provide justification for it. If we can show that our conclusion follows logically from the premises, then we have supported our position with a sound argument.

2. Factual Disagreement
In a factual disagreement people differ over whether something is or is not the case. For example, someone might think that “Hey Jude” is by Bruce Springsteen. By showing that person a Beatles CD, and showing him or her the Beatles official web page, we should be able to settle the issue. Once we have consulted an accepted authority, we can cite this evidence as proof of our point; it becomes the warrant for our claim.

3. Factual Disagreement II
Not all factual disagreements are easily resolved, of course, because sometimes the matter has not been settled. The experts may disagree, and no consensus may have been reached within a given field.

4. Factual Disagreement III
Factual statements are either true or false and refer to claims that can be confirmed or refuted by empirical observation. The claim that a product will produce accidents because of faulty design is a factual claim, although it can be crucial in a moral debate. For example, two engineers could agree on the moral principle that unsafe products should not be put on the market, but disagree as to whether Product X will produce accidents. We might describe this disagreement as to whether Product X should be marketed as a disagreement over professional ethics, but actually the disagreement hinges on different factual claims. Factual claims can be as controversial as moral claims, and it is absolutely crucial in a moral disagreement to first determine whether there is a disagreement over facts.

5. Factual Disagreement IV
The issue of global warming is an example of a factual disagreement where solid evidence is difficult to obtain. Some scientists claim that carbon dioxide, methane, chlorofluorocarbons, nitrous oxide, and other (greenhouse) gases are being trapped in our atmosphere, gradually increasing the temperature of the earth. Other scientists disagree, saying that weather records have not been kept long enough to draw any such conclusions. The higher temperatures are only minor fluctuations in an essentially stable cycle of ages, and this pattern is due to changes in the tilt of the earth and its orbit around the sun. Computer simulations can support both views, and there are equally renowned authorities on both sides of the issue, so the public is left without decisive proof of either claim (although recent evidence supports global warming).

6. Factual Disagreement V
Although in the case of global warming the facts are unclear, for the most part factual claims can be supported without much trouble. We know that Bertrand Russell died in We know that 2+2 = 4, and so forth. If we want to argue in favor of these facts, we only need to refer to reliable sources.

7. Verbal Disagreement
A verbal disagreement is another kind of dispute, involving a difference of opinion over what a crucial word means. In these cases a clear definition is needed with justification for the meaning we are using. Verbal disagreements have nothing to do with facts; they are a matter of semantics.

8. Verbal Disagreements II
A particular word may be extremely vague, so that people draw the circle of its limits differently; or a word may be ambiguous, one person employing it in one sense, someone else in another. People may have been taught to use the word differently so that the intensional meaning is unusual, or nonnative speakers may have a different extension for a word in their own language. A verbal disagreement can also arise because of the private connotation a word carries for an individual, the coloration and nuance. Whatever the cause, the reason for the disagreement is that different meanings have been assigned to the same term.

9. Verbal Disagreements III
To some extent we all live inside our heads, and various failures in communication can occur when we try to convey our private world through public language. If we suspect there could be this kind of confusion, we need to reveal the different ways that we are using words, showing that opposition to our claim may be linguistic, not factual.

10. Interpretive Disagreements
Interpretive disagreements do not concern words but are disputes about how events or actions should be construed, how stories, art, speeches, historical episodes, and so forth should be taken.
People differ in their interpretations, and fall into arguments to support their point of view.
The question of how to resolve such disagreements is more difficult than in cases of factual or semantic disputes. How, exactly, should we argue for the correctness of a particular interpretation?
Mystics have reported that they heard the voice of God speaking to them in a dream, but how can one differentiate between “God spoke to me in a dream: and “I dreamt that God spoke to me”?

11. Interpretive Disagreements II
To take an everyday example, suppose that someone you know passes by without saying hello. Should you interpret this as a deliberate snub, that the person “cut you dead,” or should you assume that the person was preoccupied, “absent-minded”?
In trying to find the best interpretation of these events, the standard we should use is plausibility. That is, we have to build a case showing that a particular interpretation best explains a situation.
Obviously, there is room for debate here, and people will build cases for different interpretations, but that is precisely what should happen. In the previous example, if you learn that your friend has just broken up with his fiancée, this lends weight to the assumption that he was very preoccupied and did not see you.

12. Evaluative Claim
Evaluative claim is the most difficult to prove. Here we are not establishing some fact, the meaning of words, or the most plausible interpretation of an event, but claiming that something should be considered good or bad. We are trying to prove a judgment about the worth of an action, a purpose, or a goal; a person’s character; or even whether some work of art or food or drink is good. Since we know the other person may not agree, we have to justify one assessment, and that is not easy when it comes to values.

13. Evaluative Claims II
For example, we may think of snails (escargot) as delicious, a tasty delicacy, while another person may regard it as a disgusting dish. Some may consider Picasso’s “Guernica”as a brilliant depiction of the horrors of war, but someone else may think of it as a fragmented, ugly painting.

14. Evaluative Claim III
Notice especially that these disputes are over the worth of something, not over how something should be interpreted. Two individuals may agree that “Guernica” depicts the horrors of war, but one may call it a bad painting and the other may call it a masterpiece. It is when people differ in their value judgements that the disagreement becomes an evaluative one.

15. Relativism
Most people feel at a loss when faced with differing values, but not knowing how to resolve value questions is not the same as knowing that value questions cannot be resolved.
When the relativist makes the claim that everything is relative she contradicts herself, for she is assuming that her own statement at least is objectively true. (A contradiction in statement.)
Carl Sagan once said, “Absence of evidence is not evidence of absence.”
We cannot start with negative premises and reach any positive conclusions; beginning with “I don’t know” we cannot end up with “Therefore, I know.”

16. Addressing an Evaluative Disagreement
Three methods may be used, separately or together, to address an evaluative disagreement. The first is to show that the opposite position is inconsistent. In the example of eating snails, for instance, if people object to the oiliness of cooked snails we could point out that they probably enjoy eating greasy french fries, pour oil on their salads and eat, and eat fat on steaks. Therefore, the fact that snails are thought slimy should not be an objection. With this approach, the other person might see that refusing to eat snails is inconsistent with his or her other food choices.

17. Addressing an Evaluative Disagreement II
An argument of this type might put an end to the opposition, because the reasons the opponent gives do not hold true across the board. Of course we would then have to present a positive argument in support of our claims, but at least our opponent’s position would have been undermined. We could then point out how good snails taste with a garlic sauce.

18. Addressing an Evaluative Disagreement III
Another method of approaching an evaluative disagreement is in terms of consequences. That is, we can show how one position would lead to good results and the opposite position would have undesirable consequences. In the case of Picasso’s “Guernica,” if we argued in favor of the painting because of its abstract balance, that would enable us to appreciate many other works – Ancient Egyptian art, Greek vases, and so forth. The consequence of holding the opposite position would be that such appreciation would become impossible. Since most people wouldn’t want to have to take that position, he or she would probably reconsider the judgment.

19. Addressing an Evaluative Disagreement IV
An even more positive method of reaching agreement about value judgments is to point out some moral consensus that exists beneath the level of the dispute. That is, if we can all agree on some basic values that underlie those in dispute, we can build upward from that common ground. If someone opposes lying, we could point out that lying might be appropriate if an estranged husband comes through your door with a gun and asks you if you’ve seen his wife. You know that his wife is in the basement but you lie to protect her. You may convince your opponent that lying may be morally justifiable in certain cases.

20. Values
If we reach down to fundamental criteria for evaluation such as alleviating suffering, protecting property, preserving human dignity, supporting freedom, and so forth, moral consensus can be a powerful method for arguing.
From Values to Value Assumptions:
To identify value assumptions, we must go beyond a simple listing of values. Others share many of your values. Wouldn’t almost anyone claim that freedom of speech, justice, and honesty are desirable?

21. Values II
According to M.Neil Browne and Stuart Keeley, look again at the definition, and you will see that, by definition, most values will be on everyone’s list. After all, these are ideas that reflect our collective dreams as a species. Because many values are shared, values themselves are not a powerful guide to understanding. What leads you to answer a presciptive (the way things ought to be) question differently from someone else is the relative intensity with which each of you holds specific values.

22. Values III
That we attach different levels of intensity to specific values can be appreciated by thinking about the responses to controversies when pairs of values collide or conflict. While it is not very enlightening to discover that most people value competition and cooperation, we do gain a more complete understanding of prescriptive choices as we discover who prefers competition to cooperation when the two values conflict.

23. Typical Value Conflict and Sample Controversies
Loyalty-honesty.
Competition-Cooperation
Order – freedom of speech.
Should you tell your parents about your sister’s drug habit?
Do you support the grading system?
Should we imprison those with radical ideas?

24. Resolving disagreements
Factual disagreements. If we are arguing a matter or fact, we support our claim by citing evidence from some authoritative source that proves our point. This can be an encyclopedia, chart of statistics, expert testimony, and so forth.
Verbal disagreements. In the case of a verbal dispute we need to show how we are defining key words, and argue for particular meanings that are important to our exposition. This is usually done by referring to conventional usage.

25. Resolving disagreements II
Interpretive disagreements. The standard used in this type of disagreement is plausibility. Here we build a case showing that a particular interpretation best explains the event, person, action, story, and so forth.
A. Two contradictory interpretations cannot both be true.
B. Some interpretations are clearly false, but several may be plausible and capable of being defended.

26. Resolving disagreements III
Evaluative disagreements. Three approaches can be used, individually or in combination, to try to settle this dispute. We can:
A. Describe how the reader would be inconsistent in holding the opposite view.
B. Show the desirable consequences of maintaining our position.
C. Establish some moral consensus that underlies the disagreement and is self-evident and fundamental.

27. Truth and Relevance in Arguments
In constructing a sound argument or in evaluating whether an argument is worth accepting, we must consider four key factors: truth, relevance, adequacy, and alternatives.
Truth is an essential ingredient in any sound argument, and insofar as we can, we want to be sure that what we maintain is in fact so. But how do we know when a statement is true? What mode of truth should be used to establish truth in our argument?
"Truth is a shining goddess, always veiled, always distant, never wholly approachable, but worthy of all the devotion of which the human spirit is capable." - Bertrand Russell

28. Pragmatism
One theory, a distinctively American one, is called pragmatism, which declares that a statement is true if it works. That is, if we state that something is true we can expect certain practical consequences to follow from it. If what we anticipate does not occur, then the statement is false. For example, if we say that steel girders will be able to support the weight of a bridge, and they do hold up the bridge, our statement becomes true.

29. Pragmatism II
In the same way, if we say that belief in God gives us greater hopefulness and security, and these feelings do in fact occur, then these beliefs work for us and can be declared true.
Whether we are writing about science, engineering, ethics, politics, religion, or what have you, the test of truth for the pragmatist is expediency or workability.
Unfortunately, this standard of truth has some defects. For one thing, the pragmatist assumes a statement becomes true in the future, whereas we ordinarily assume a statement is true or false now; it is only proven true later.

30. Pragmatism III
More important, in areas such as religion, the pragmatic test of truth is much like wishful thinking. That is, if faith in God and life after death makes us feel good, then the pragmatic pronounces it true. But we should not believe something because it is comforting, but because it is so. Some truths are happy ones, others are bitter ones, but a statement is not true just because it makes us happy.

31. Coherence Theory of Truth
The coherence theory of truth holds that if what we claim is consistent with other ideas that are taken to be true, then our claim is also true. In other words, if our statement fits in with other truths then it too can be taken as true. If an equation is x + 2 = 5 and we state that x = 3, then we are correct because it fits with other parts of the equation.
“When one is frightened of the truth…then it is never the whole truth that one has an inkling of.” – Ludwig Wittgenstein

32. Coherence of Theory II
The coherence theory is useful when we cannot check the facts directly but must rely on agreement with surrounding information. This is often the case in arguments about history, mathematics, or anthropology. Theologians use a coherence standard very frequently in trying to show how religious explanations make sense of the facts we know.
This theory has serious defects that make it unreliable. For example, some mystics have claimed that the is earth is on the back of a turtle, and that the clouds are turtle’s breath, and so forth. All of this is consistent, but it is hardly true. The parts hang to together consistently, but there is no truth to it whatsoever.

33. Correspondence Theory of Truth
The most accepted view of truth is called the correspondence theory. It maintains that a statement is true if it accurately represents reality. That is, a statement is true if it describes things as they ae, if it tells us what is so. We call a sentence false if it fails to reflect reality, falsifying or distorting what is actually the case.

34. Correspondence Theory of Truth II
Although the correspondence theory has some defects and limitations, it seems stronger than the coherence approach. As we will see in discussing formal reasoning, the form of an argument may be perfectly correct in the sense that the conclusion follows from the premises, and yet the vital element of truth may be missing. Ideally, an argument should have both a logical form and true statements, but certainly truth must present or the argument simply is not sound.

35. Correspondence Theory of Truth III
A further factor in proving our claim is relevance, which refers to whether the reasons o evidence apply to our conclusion. We violate this rule if we say that Tony will never be a basketball player because he can’t crochet. Determining relevance can be difficult. The debate over affirmative action, for instance, turns on the question of whether a candidate’s race is a relevant consideration in hiring, school admission, and so forth.
Should women be prohibited from having a combat role in the military? Is gender relevant?

36. Adequate Proof
Once we determine that our evidence is true and relevant, we need to consider whether it is adequate to prove our point.
If we were to write that Seattle gets a lot of rain, graphing years of rainfall records from Seattle would prove our point.
If we were to write that the world is going to end tomorrow and our proof is that we saw a man on the street corner carrying a sign stating that the end is near, we have inadequate proof to support our argument.

37. Alternative Possibilities
A final factor to be considered in argument is that we ought to choose the best alternative that we can imagine. The alternative we hit upon may be superior in efficiency, elegance, cost, value, and so forth, but if it is genuinely preferable in some respect then it deserves to be promoted.
For example, we could argue that we can get rid of all of our trash by throwing it into landfills This would be true. However, recycling much of the trash would be a more forward, earth friendly, elegant alternative. We should choose the most elegant alternative.

38. Summary Truth – it represents reality accurately.
Relevance – it contains pertinent reasons.
Adequacy – it provides sufficient proof of our claim.
Alternatives – it offers the best possibility that we can imagine.