Summary with the 4th edition of Critical Thinking: a Concise Guide by Bowell and Kemp

What are the basic concepts about arguments? - Chapter 1

Every day we are bombarded with written and spoken messages (for example advertising) about what we should (or shouldn’t) do, buy or believe. This forces us to either ignore or accept certain messages without thinking too much about them, or, at the complete opposite, think very explicitly about them and our own behaviour in buying or consuming things. In the latter case, they are making you look for a reason. However, we are not only looking for a reason for our actions or beliefs, but also for justification, or at least a good reason. Giving an argument indicates persuasion by giving good reasons.

Recognizing arguments

Rhetoric refers to any verbal or written attempt to convince someone of something purely through the power of words, without attempting to give good reasons. It is thus not the same as an argument, which tries to give good reasons for doing or believing something. Officially, threats and bribery would also fall under the topic of rhetoric, but because the person who is convinced technically does have a reason to do something, these forms are often not taken into consideration. Rhetoric techniques can be manipulative and compelling but are not always undesirable (just think of President Obama's speech).

If a persuasion attempt does come in the form of an argument, this does not necessarily have to be a good argument. Analysing a persuasion attempt is done in three steps. First, it must be considered whether an argument is presented by identifying the case in question. Second, the argument must be reconstructed, clarifying the steps and form of the argument's reasoning. Finally, we must evaluate the argument, and assess what about it is and is not correct.

All arguments can be seen as attempts for reasons to think that a claim is true. However, a single claim is not the same as an argument. An example of an unsupported claim is, for example, "it will rain later." When we’re speaking of an argument, it means the claim also has a support, for example: "it will rain later because my weather app says so." An argument therefore consists of two parts: the primary claim (the conclusion), aka what we want to convince others of, and the supporting statements (the premises). The definition of an argument is therefore as follows: a set of propositions of which one is the conclusion and the remainder are premises, intended to support the conclusion. Proposition refers to the actual content of a declarative sentence that can be expressed by multiple sentences.

Significant aspects

Depending on how we use a sentence, it can express different aspects of meaning in addition to the actual content. For example, the rhetorical force indicates the rhetorical aspect of the sentence, or the emotional or otherwise suggestive presentation of the content message, such as sad looking kids above an advertisement for a charity. The implication indicates meaning that is not literally said but can be reasonably deduced given the context. This can be a form of rhetoric if the implicated aspect is used to elicit responses that are motivated by emotion or prejudice, such as, ‘Well, I see that at least this time you’re not cheating on your girlfriend.” You don’t say someone is cheating on a general basis, but you are implying it. A definition tells us what is needed for something to qualify as a certain type of thing (for example, a dictionary definition). The definitions used in this book, for example, are types of definitions that gives us the necessary and sufficient conditions to count as a certain thing. For example, an ewe is necessarily a sheep and feminine, and those two conditions are enough to say that something is one. You can test definitions by giving counter examples. A counterexample is something that meets the definition but is not an example of what is being defined, or something that is an example of what is being defined but does not meet the definition. Such as, a table has a flat surface and two legs. However, a bed has a flat surface and four legs too, yet it isn’t a table.

Standard form

Arguments for analysis are plotted in a certain form. The premises are put under each other in the order in which they occur in the thought process and are numbered with P1, P2, etc. A line is placed between the last premise and the conclusion (C) ( aka the inference bar ). This shape is called the standard shape . If you reconstruct an argument argument reconstruction is called the standard form. An example of this is:

P1) Helping someone to commit suicide is the same as murder

P2) Murder is bad .

C) Helping someone to commit suicide is bad.

Identifying conclusions and premises

To see if a speaker or writer puts forward an argument, the context is very important. Based on this you can interpret the intention of the writer or speaker.

A number of points are important for identifying a conclusion. First, it is useful to identify and paraphrase the main point that the writer or speaker puts forward into one simple proposition. Some premises or conclusions must be rewritten, for example if they are put into question form. In addition, it is important to remember that a text can contain multiple, extensive arguments that together lead to the main argument. It is also useful to pay attention to words that are known as conclusion indicators , such as 'so', 'therefore', 'in short', etc. If a text contains no indicators, it is sometimes possible to identify the conclusion by inserting indicators yourself. If these fit well, it is likely that you have identified the conclusion. However, when paraphrasing the argument, the indicators should be omitted.

A number of points are also important when identifying premises. First, you can ask yourself what the reasons are for the speaker or writer to believe his conclusion. It can also help to separate the rhetoric and non-relevant parts of the text from the actual content. You can also search for premise indicators , such as 'because', 'the reason for this is', ‘since’, etc. Just as with the conclusions, you do not use these indicators when paraphrasing. Finally, it is important to pay attention to implicit premises or conclusions, for example if the speaker or writer assumes that, given the context, the audience is already assuming something in particular and thus isn’t worth mentioning.

Arguments and explanations

Words that function as indicators can sometimes be difficult to distinguish from words with other functions. For example, it is important to distinguish between arguments and explanations. For example, 'because' can be used to introduce both an argument or explanation. In the first case, an attempt is made to convince someone that something is like this (I think the tap is leaking because I hear it dripping into the bathroom), in the second case, it is already accepted that it is like this (The tap is leaking because it is rusting). This dual function also occurs when working with words such as 'therefore', 'so', etc.

Interim conclusions

Between Conclusions (intermediate Conclusions) are all of the conclusions drawn on the road to the main claim. Sometimes a text temporarily focuses on a part of the argument, where we can speak of inference from, for example, P1 and P2 to C1 and from C1 and P3 to C2.

Arguments come in various forms and they make up a large part of our daily lives. If you develop an ability to understand others' attempts to persuade you and you can figure out their arguments, you can also see what the ‘good’ reasons are for doing or not doing something. But why is it important to get good reasons before you are persuaded? An important reason is that you can get closer to the truth this way. In addition, making good, well-founded decisions is sometimes of vital importance (just think of the decisions that a judge must make). Critical thinking is therefore important.

How do you interpret linguistic elements and rhetorical techniques? - Chapter 2

Linguistic phenomena

The interpretation of speech or text is often hampered by all sorts of linguistic phenomena in everyday language. A number of these phenomena are discussed below.

Ambiguity

A sentence is ambiguous if there are several ways to interpret it. In lexical ambiguity, a word has two or more meanings; a ‘bank’ can both be by the side of the river s well as an institute that helps you save money. The context often helps to correctly interpret the word. However, if the two meanings of a word are close together, this becomes more difficult. For example, if someone says: the average mortgage has doubled in the last six years, he can mean that the mortgage that people took out six years ago has doubled. However, he can also mean that the average mortgage that is now taken out is twice as high as the average mortgage that was taken out six years ago. In syntactic ambiguity, the sentence order allows different interpretations, such as in the sentence "woman admits to having driven dangerously in court" (she admits, in court, that she has driven dangerously before, or she admits that she took the car into the court and drove dangerously).

Vagueness

Vagueness is often confused with ambiguity but does not indicate the same. Many charged words that appear in public language use are vague, such as 'rights', 'liberal' or 'sexism'. For instance, ‘this is war’, can mean many things. Words can also be vague in a more philosophical way, such as "orange," "thick," and "city." With such words, there is no clear demarcation for when something can or cannot be called that.

Primary and secondary connotation

Each noun and an adjective refers to a specific amount of things, which is also called the range (extension) of the word. For example, different types of squares fall within the scope of the word "square." The primary connotation of a word corresponds to the definition (for example, a ram is a male sheep). However, words also have additional characteristics (for example, a ram has a woollen coat and horns); these are not necessary for the definition and fall under the secondary connotation. This distinction is important for, for example, recognizing vague words; it is often difficult to say which properties fall under the primary or secondary connotation. In addition, the secondary connotation can be used as a rhetorical force. A special form of this is the secondary connotation of metaphorical use of language. If you call someone a pig, this is mainly about the secondary connotation of the word (dirty, greedy, etc.).

Rhetorical questions

Rhetorical questions have a questioning form, but indirectly contain a proposition that is supposed to be a generally known fact. However, the latter is not always the case.

Irony

There is irony if someone says it is actually the opposite of what they want to convey (for example, "what a nice weather" when it rains and storms). One’s tone of voice often indicates the use of irony.

Implicit relative sentences

With implicit relative sentences, a comparison is made with a certain group, but that comparison is not explicitly stated. This is for example the case with "we have a low apartment rent", or "she has an above average salary". They compare or average with something, however, it is not quite stated what this something is. These sentences are often vague and have little informative value.

Problems with quantifiers

Quantifiers are words that indicate a quantity or a frequency, such as "all", "too much", "nine", "always", etc. Quantifiers can cause three problems. First, quantifiers are not always used with sufficient precision (for example, when you say, "all students are poor", while you actually mean "a lot" or "almost all"). Secondly, some quantifiers themselves are vague, such as "some." Finally, people often omit quantifiers, such as “students don't put enough effort in their work”. With sentences like those, it is often not clear whether you mean all students, most students, the students at your school, etc. You can use counterexamples to test such generalizing sentences.

Quantifiers and generalizations

A generalization is a statement about a category of things, such as "all eggs have an egg yolk". Here we can make a distinction between soft generalizations (where actually quantifiers are implied as "often" and "usually"), and hard generalizations (where really quantifiers are meant as "none", "never" or "always"). Hard generalizations are often used for prejudices about certain groups of people, which is dangerous, because people often interpret hard generalization as such.

Rhetoric moves

An attempt to convince without giving a good reason or motivation is called rhetoric. This includes the categories rhetorical moves and fallacies. Fallacies are argumentative but contain generally incorrect or poor reasoning. Rhetoric moves are non-argumentative and appeal to feelings and emotions instead of reason.

There are different types of rhetorical moves. This way they can appeal to specific feelings. Calling on novelty appeals to the desire for new things and trends and our fear of missing out on trends or improvements (FOMO). Calling on popularity appeals to our desire to go with the masses and our confidence that popular products are better than non-popular ones. Recourse to pity or guilt appeals to our conscience through the generation of pity or guilt (such as advertisements for charities). Appealing to cuteness appeals to the appeal of cute things, such as children, (young) animals or animations. Also appealing to sexiness, wealth, status, hipness, etc. appeals to the attraction that we feel with these things. Calling on fear is widely used in politics, for example when exaggerating the danger of immigrants to make people opt for a stricter immigration policy. Appeal to derision takes place when a speaker or writer attacks the position of the opponent by pulling it into the extreme and thus making it ridiculous.

In addition to appealing to specific feelings, there are a number of other commonly used rhetorical moves. The direct attack often takes the form of a simple slogan, such as "drink cola!". Buzz words are words that have a lot of rhetorical power because of their rich secondary connotation, such as "change" in political campaigns. Scare quotes indicate the use of quotation marks to make the words of an opponent charged or ridiculous, such as "My opponent will have his 'reasons' for his actions". When acting on an ambiguity, the vagueness or ambiguity of a word or concept is deliberately used. For example, if the newspaper says that a certain person has "ties" with a terrorist organization, most people assume that that person is a terrorist. However, there are several other - less negative - ways in which someone can have a connection with that organization. Acting on implication means assuming the implications that a sentence brings. If a politician says, "If the government raises the income tax, the working families will suffer," it implies that the government actually intends to do this. However, that is not said literally and does not have to be that way. Another move is to ask leading or complex questions. An example of this is when you say, "Are you still beating your wife?", this assumes that it is true that you are beating your wife. The raising of a smokescreen indicates distracting the attention of the subject through rhetoric (for example, subtly changing the subject). A final rhetorical move is the use of the spin technique, where rhetoric is used to adjust the opinion of others. For example, if the government gives money to banks, they use the term "injecting liquidity" to make an extra impression on people.

The interpretation of speech or text is often hampered by all sorts of linguistic phenomena in everyday language. A number of these phenomena are discussed below.

How do you analyse the structure of deductive arguments? - Chapter 3

Frustration often plays a role in discussions with others. This frustration comes from two sources. First of all, when confronted with an argument, it is often difficult to keep this clearly in mind. To counter this, argument reconstruction is important. Secondly, it is often difficult to state what exactly is wrong about another's argument. Techniques and conception with regard to argument assessment are important for this. The argument assessment is first discussed below.

The charity principle

An argument consists of a set of propositions, or premises. However, these premises are not always explicitly stated. That is why the first step in evaluating an argument is clarifying and supplementing the literal words of the speaker/writer. Reconstructing an argument is largely a matter of interpretation, but with the charity principle we can still do this in a systematic and conscious way. The charity principle firstly includes the context and circumstances in which someone says something. Together with the actual words that the speaker/writer uses, the context and circumstances form the basis for assessing an argument. If we want to find out the truth (and not just win the discussion), we must always choose the best reconstruction of the argument. If you show that something is a bad argument, that does not mean that the conclusion is not correct. However, if you show that something is a good argument, you will learn something about the correctness of the conclusion. Hence the charity principle. However, this principle has limits; the only evidence you can rely on is the context, circumstances and words of your discussion partner. If you start thinking too much about what that person might mean, there is a chance that you will insert new arguments yourself. If you only want to reconstruct the other's argument, that is not very handy. If your goal is to get closer to the truth, however, this may be the right approach.

Truth

Truth should not be confused with the beliefs (beliefs) that someone has. When person A says, "fish live in the water", he means that he believes that fish live in the water. If person B says, "that's true", this person means he believes that too. Whether it is true that fish live in water does not, however, have to do with whether people believe it or not. The truthfulness of a statement says something about whether a statement is true or not. In the formal study of logic, it is important that a proposition cannot be both true and false at the same time.

Deductive validity

Deductive validity is the derivation of a specific statement by making assumptions. An example of this is:

P1) The president's dog is infected with fleas

P2) All fleas are bacteria.

C) The president's dog is infected with bacteria.

That such a reason is valid does not necessarily mean that the conclusion is true. If the reasoning is correct while one of the premises is incorrect, the reasoning is valid, but not true. Validity is therefore about the connection (inference) between the premises and the conclusion, not about the truth content. However, if the premises are all true, the conclusion is necessarily true. If it is not, then the reasoning must be invalid. Logic is therefore about constructing perfectly reliable procedures to detect validity, or the lack thereof.

Prescriptive claims versus descriptive claims

Descriptive claims are claims that only describe the facts (The cat is lying on the mat). Prescriptive claims are claims that say how things should be based on, for example, wishes, values, norms or moral rules (You must ensure that the cat is on the mat).

Conditional propositions

Conditional sentences are often expressed in the if-then form (for example: if it rains, then it is cloudy). You have different forms of conditional sentences:

1. If not .. then not ..

If P is Q, then also applies:

If not P, then not Q.

2. Or .. Or ...

This form can be used inclusive, where applies; or P is true, or Q is true, or they are both true. This form can also be used exclusively, whereby; or P is true, or Q is true, but not both. For both exclusive and inclusive, both P and Q cannot be false.

3. Only if ...

Hereby it applies that if P, then Q, but the other way around it does not. For example, if you say: It only rains when it is cloudy, you cannot say: it is only cloudy when it rains. This should not be confused with 'if and only if'. For example, if you say: "Sarah only comes to the party when Joop comes too," it is possible that Sarah will not go to the party when Joop goes. However, if you say that Sarah comes if and only if Joop comes, it means that if Joop comes to the party, Sarah will come anyway.

4. Unless ..

It is easiest to see 'unless' as equal to 'if not'. For example: "I don't make the bus unless I run" is the same as "I don't make the bus if I don't run".

The antecedent and consistent of a conditional sentence

The relationship between two parts in a conditional sentence can be represented in the form of an arrow, for example: It's raining à It's cloudy. The part where the arrow comes from is called the antecedent and the part where the arrow goes is called the consistent.

A conditional sentence does not necessarily have to be an argument. If you say, "If it rains, it is cloudy", is not the same as saying that it rains. In argument form this would be: It's raining, so it's cloudy. This is sometimes confusing because in everyday language a conditional sentence often implies that the antecedent is actually true. Arguments can, however, have a conditional sentence as a conclusion.

Argument trees

An argument tree is a tool that is used to present arguments in diagram form. The claims and premises are represented by Cs and Ps in circles, with an arrow going to C1 from P1 and P2, and an arrow to C2 from C1 and P3. If a C can be derived independently from P1 and P2, a separate arrow goes to both from P's. If C can only be derived in combination from, for example, P1 and P2 or P3 and C1, a joint arrow goes to C2.

Deductive accuracy

A deductively correct argument means that an argument is valid and that all premises are true. In result, that it is not possible for two opposing points of view to have a deductive argument, because that would mean that two opposing conclusions are both true. If an argument is deductively incorrect, it means that the argument contains either an incorrect premise, that the conclusion is invalid, or both.

The connection with formal logic

There are several valid argument schemes, the argument being valid regardless of the content (so it says nothing about the truth content):

1. Modus ponens:

P1) If P, then Q.

P2) P.

C) Q.

2. Modus tollens:

P1) If P then Q.

P2) not-Q.

C) not-P.

3. Disjunctive syllogism:

P1) P or Q.

P2) not-P.

C) Q.

In addition, formal logic uses surrogate characters instead of the logical language expressions:

Brackets are also used to distinguish arguments: for example, P (Q v R) means that if P is true, or Q or R is true, and (PQ) v R that is, or “If P, then Q” is true, or R is true. However, certain logical words are often used, such as "all". The use of surrogate signs is sometimes more convenient than the linguistic constructions that we use in everyday language, because in formal logic there is only one way to express a certain argument.

Frustration often plays a role in discussions with others. This frustration comes from two sources. First of all, when confronted with an argument, it is often difficult to keep this clearly in mind. To counter this, argument reconstruction is important. Secondly, it is often difficult to state what exactly is wrong about another's argument. Techniques and conception with regard to argument assessment are important for this. The argument assessment is first discussed below.

How do you analyse the structure of inductive arguments? - Chapter 4

As mentioned in earlier chapters, care must be taken when generalizing claims and combating them. For example, if a doctor says that a vaccination against hepatitis A prevents you from being infected with hepatitis A, you can give as a counter argument that you know someone who was infected after vaccination. This is because the vaccine offers 99% protection. This counter argument barely disputes the doctor's claim, you could even say that it doesn’t; what he most likely meant to say is that a vaccination makes the chance of infection very small.

Inductive power

An argument is inductively powerful if it is not deductively valid, but still the conclusion is probably true. An example of this is:

P1) Fiona lives in Inverness, Scotland

P2) Almost everyone in Inverness, Scotland, owns at least one woollen garment

C) Fiona has at least one woollen garment

Although this argument is not deductively valid, but based on the assumptions, the conclusion is plausible. We can solve this by putting the word "probable" before the conclusion. Inductive power has to do with probability.

Probability

The probability that a proposition is true, is often expressed on a numerical scale between 0 and 1. There are three ways to explain probability: proportion, frequency and rational expectation. The proportion is expressed in quantifiers such as "most" and "7/8 of". For example, the chance to draw an ace from a deck of cards is 4/52 (0.077). With the frequency you look at how often something occurs. If it has snowed 14 times in the last 100 winters, you can infer that the chance that it will snow in the coming winter is 14/100 (0.14). The degree of rational expectation is our most common concept of probability calculation. Here you reason what the most likely option is, based on the evidence you have (for example, frequencies or proportions). Conditional probability calculation plays a role in this. For example, if you have a closed card in front of you and the only information you have, is that this is a red card, you know the conditions for calculating the probability. Because spades and clubs are black, you can argue that there is ½ chance that it is a heart card, and ½ chance that it is a diamond card.

An argument is therefore inductively powerful if the conditional probability of the conclusion relative to the premises is greater than ½, but less than 1. The argument is still not deductively valid, but it is more likely that the conclusion is true than not true. There are a number of important points to keep in mind when talking about probability and inductive power:

1. Sometimes opportunities are not expressed as conditional opportunities. For example, we assume that the probability of an ace is 1/13, assuming that the conditions are met (for example, that the deck of cards is complete). However, this type of implicit premise must always be kept in mind.
2. Opportunities should not be seen as an alternative to the truth or as an intermediate form between true and false. Opportunities say something about how likely it is that a proposition is true.
3. Probability calculation is a matter of the degree to which something is likely. However, this is not the case with truth; something is either true or false. In contrast to deductive validity, inductive power is therefore also a question of probability
4. The everyday use of terms such as "probable" and "most" is often vague; unless specified, it merely indicates that the probability that something is true is more than ½. Often, however, a substantially larger part than half is meant. When assessing inductive arguments, it is important to indicate the degree of inductive power as accurately as possible.
5. Rational expectation of probability is about what is reasonable in reality, not what a particular person thinks is reasonable.
6. The degree of inductive power depends on the truthfulness of the assumptions. The receiver will often (just like the sender) have an "intuitive" or emotional assumption of something and perceive this as truth as part of the consideration. In everyday language, not everything has a mathematical meaning.

Inductive accuracy

An argument is inductive if it is inductive and the premises are true. However, unlike deductive accuracy, the conclusion does not necessarily have to be true; Inductive accuracy is about probability. The premises of an argument can also contain opportunities instead of quantifiers, for example the word "likely".

Arguments with multiple probability assumptions

If probability elements occur in several premises, it is possible that the inductive power is reduced by the collective opportunities in the premises. For instance:

P1) Jon probably left home on time.

P2) Jon probably wasn't in a traffic jam.

P3) If Jon has left home on time and has not been in a traffic jam, he will arrive at work on time.

C) Jon is probably on time at work

This argument is not inductive because the collective probability of P1 and P2 exceeds the probability of ½.

With the above argument the premises are independent (they each support the conclusion separately), but premises can also be dependent . For instance:

P1) Most Americans are people born in America

P2) Most people born in America are white.

C) Most Americans are white.

This argument is not inductively powerful. Strictly speaking, "most" can also mean just over half. Then it could be that only a little more than ¼ (½ x ½) of the Americans are white and the conclusion would therefore be incorrect. The same problem can occur with dependent premises that contain the word "likely".

Inductive power in extensive arguments

The conclusion of an inductively powerful argument can serve as a premise for a subsequent conclusion that in turn can be deductively valid, inductively powerful or neither. However, if any sub argument of an extensive argument is not deductively valid, the entire argument is by definition not deductively valid (but possibly deductively powerful).

Conditional opportunities in the conclusion

A conclusion can also contain the word "likely", as in the example below:

P1) Most students who study mathematics complete their propaedeutic year in one year

C) If you are going to study mathematics, you are likely to get it in one year.

Proof

In some cases, for example when gathering evidence for a murder case, multiple premises together can provide inductive power. One of the premises (person X had the option of committing the murder) would then not be inductively powerful, but with multiple premises together it would be (for example: person X had the wish to see the victim dead).

Inductive inferences

Inductive inference is the term for extrapolating a sample from a total population to the entire population. There are two types of inductive interference: in the first you make the inference from a certain number of observations to one or a few new cases, in the second you make the inference from a certain number of observations to all cases.

With both types it is important to determine how representative the sample is for the entire population. View the following example:

P1) Every observed bear is white.

C) All bears are white.

Since not all bears are white, the sample in this case was not very representative (for example, only polar bears were observed). When determining the representativeness of a sample, it is important to look at all factors that may have correlations with the observation (in the case of the polar bear: living environment, weather conditions, etc.). In general, the more representative and larger the sample, the stronger the inductive inference. Moreover, an inference to "most" of the total population is stronger than an inference to "all".

Induction and deduction

An inductive reasoning can be all cats that I have seen in my life have pointed ears, so cats have pointed ears. You can convert this into a deductive argument by saying: (A) all cats that I have seen in my life have pointed ears + (B) if all cats that I have seen have pointed ears, then all cats have pointed ears. Makes: (C) so all cats have pointed ears.
There is nothing wrong with the reasoning in itself, although in reality it is more likely to say, if all the cats I have seen have pointed ears, then probably all cats have pointed ears.

Another problem that may arise with these reasoning is to explain with the following example. (A) All Party for the Animals voters are vegetarian. (B) 1 in 20 non-Party for the animal voters are vegetarians. (C) Carl is a vegetarian, so he votes Party for the Animals.

Even though this sounds very likely, it is unlikely. Suppose 2% of the 16 million Dutch people vote for Party for the Animals, that is 320,000 Dutch people. In addition, 5% (1 in 20) of those 16 million Dutch people are vegetarian, that is 800,000. The chance that you will come across a vegetarian who does not vote for the Party for the Animals is therefore greater than that he or she votes for the Party for the Animals.

An assessment program

Argument assessment falls into two categories: logical assessment (assessment of deductive validity and inductive power) and factual assessment (assessment of the truthfulness of the premises). However, the evaluation of inductive power is not completely independent of the facts in the way that this is the case when assessing validity. In the case of inductive power, the assessment also depends on factors such as the representativeness of the sample.

As mentioned in earlier chapters, care must be taken when generalizing claims and combating them. For example, if a doctor says that a vaccination against hepatitis A prevents you from being infected with hepatitis A, you can give as a counter argument that you know someone who was infected after vaccination. This is because the vaccine offers 99% protection. This counter argument barely disputes the doctor's claim, you could even say that it doesn’t; what he most likely meant to say is that a vaccination makes the chance of infection very small.

What arguments in the standard form are there? - Chapter 5

The purpose of argument reconstruction is to produce a clear and explicit version of the original argument of the writer/speaker. The argument will ultimately be in standard form.

Unnecessary material

The first step in reconstructing an argument is to remove unnecessary material, or everything that does not play an argumentative role. These can be things that the speaker/writer has aimed for, for example, emphasis or rhetorical elements. Below some examples of unnecessary material:

1. Internship setting: pointing the reader to the material being discussed and emphasizing the seriousness and importance of the problem.
2. Dressing the conclusion: the conclusion is often drawn up in an attractive or convincing way. However, this must be converted into one simple proposition.
3. Phrases such as "it is clear that" or "as everyone knows": these must always be removed from reconstructed arguments.
4. Words such as "because", "therefore" and "therefore": these are superfluous in the standard form and must therefore be removed.

Remove rhetoric

To clarify the argument, rhetorical elements must be removed. A metaphor is a form of imagery, such as: "The director has loose hands". This sentence must be converted into a reconstructed argument, for example: "The director is violent". An expressive epithet is a term for a person, group, or other entity that is used only for rhetorical purposes, such as: "The manipulative tyrant," which in a reconstructed argument should simply become "The Director." Street language (slang) and rhetorical questions must also be avoided in the reconstructed argument.

Logical streamlining

In chapter 3 we saw that logical relationships can be used in different ways. For example, "A unless B" means the same as "If not B, then A". When reconstructing arguments, we must try to formulate logical relationships in the simplest, clearest and best-known manner possible. This is often necessary for texts in which the logical relationships are represented in a complicated, confused or hidden way. There are two rules of thumb for logical streamlining:

1. Where applicable, rewrite sentences as either conditional or disjunctive sentences in one of the following forms:

2. Rewrite generalizations in one of the following forms, where ___ is entered by "all", "most", "some", "note", "almost all", etc.

Implicit and explicit

Essential propositions are often omitted from the arguments that have been set, or implicitly stated. These propositions must be made explicit during the reconstruction . You do this by putting all the intentions of the writer / speaker in the argument, creating a deductively valid or inductively powerful argument. For example, if someone says: “Is Mrs. Jansen highly educated? Of course! Did you not know that she is a successful politician? ”, Could you reconstruct this as:

P1) Mrs. Jansen is a successful politician

C1) Mrs. Jansen is highly educated

However, the argument is not deductively valid or inductively powerful; a premise is missing that isn’t said and only implied. Thus. we must make this explicit, for example:

P1) Mrs. Jansen is a successful politician

P2) All successful politicians are highly educated

C) Mrs. Jansen is highly educated

Connecting premises

A premise that must be made explicit to make an argument valid is called a binding premise . Connecting premises are often omitted in everyday language, because they are supposed to be general knowledge. If someone says: “My cat will not have kittens; it has been sterilized ”, it is assumed that everyone automatically understands the connecting premises. A reconstruction would look like this:

P1) My cat has been sterilized.

P2) Cats that are sterilized cannot have a litter.

C) My cat can't have kittens.

However, it should not simply be assumed that an argument that is not deductively valid or inductively powerful would be if the intended binding premises were to be made. Sometimes the implicitly binding premise is simply not true.

Covering generalizations

View the following example:

a. If Betty is a Siamese cat, she has blue eyes.

b. All Siamese cats have blue eyes.

We can say that (b) is a comprehensive generalization of instance (a). However, we can also say: "If X is a Siamese cat, it has blue eyes." When people use conditional sentences such as these, they often do this on the basis of a comprehensive generalization. When reconstructing an argument it is important to use the covering generalization instead of the conditional proposition.

Relevance

If a proposition is not relevant to the reasoning of the conclusion, it must be omitted. For example, P2 is irrelevant in the argument below:

P1) Restaurant "The cheerful Frenchman" is usually fully booked.

P2) I went to eat once at The cheerful Frenchman.

C) The cheerful Frenchman is probably fully booked tonight.

In everyday language you would call P2, for example because you want to emphasize your knowledge about the restaurant in question. However, for the argument itself it is not relevant and must therefore be omitted from the reconstruction. In addition to the fact that P2 is not relevant, there is another reason to omit this proposition. Suppose, for example, that the person to whom you present the argument finds out that P2 is not true, then the entire argument becomes invalid (since both premises must be true). However, if you remove P2, the argument is valid.

Ambiguity and vagueness

For an explanation of ambiguity and vagueness, see Chapter 2 (How do you interpret linguistic elements and rhetorical techniques?). Below is explained how you can deal with these concepts in reconstructing arguments.

Ambiguity

If there is ambiguity in the original argument, we must look at what the speaker/writer's most likely intention was. Then we must reconstruct the argument in such a way that there is no longer any question of ambiguity. For example, if an advertisement states that a restaurant is "the leading restaurant in Amsterdam", you can reconstruct the argument in (at least) three ways. It is possible that the restaurant serves the best food, but it is also the largest restaurant (for example McDonalds), or the most profitable restaurant. In the last two reconstructions there is really no good reason to eat at that restaurant (if you are looking for the best food).

Vagueness

Words such as "orange" or "bald" are vague in the scope that is meant (Does bald mean no hair at all or does it also count when only the top of the head doesn’t have hair anymore?) The biggest problems in reconstructing arguments, however, arise with words that are vague in their meaning. The best way to solve this is simply to omit these words from the reconstruction. Consider the following example: “The politician has shown by his preference for traditional values ​​that he is conservative. It is therefore certain that he will advocate stricter penalties for criminals. " The word "conservative" is vague and rhetorically charged, so let's omit it in the reconstruction of the argument:

P1) The politician has a preference for traditional values

P2) Most people who prefer traditional values ​​favour stricter penalties for criminals.

C) The politician will probably advocate stricter penalties for criminals.

However, it is not possible to remove all forms of vague language. This will be discussed further in the next chapter.

More about generalizations

As we saw in Chapter 2, we can distinguish between hard and soft generalizations. Because quantifiers such as "all" or "none" are often omitted, confusion can sometimes arise as to what type of generalization is meant. When reconstructing arguments, quantifiers must always be used to prevent this confusion.

The scope of an argument is about the extent of the number of cases that is meant. For example, the range of "all cows are herbivores" is wider than the range of "all black cows are herbivores". As a general rule, when reconstructing arguments, we should not use harsh generalization if it creates doubt that could be eliminated by using a narrower range. However, choosing a narrower range is not always better: the insertion of "black" adds nothing to the above arguments about cows.

Practical reasoning

Practical reasoning indicates arguments with a practical conclusion. This type of reasoning is based on two considerations. First, an outcome is specified as either desired or undesirable. Second, it contains a proposition that says one of the following things:

1. If action X is executed, the result will be the result.
2. If action X is executed, the result will not be the result.
3. If action X is not implemented, the result will not be the result.
4. If action X is not executed, the result will be the result.

So there are eight different types of arguments about a relationship between action and result. When assessing such arguments, however, a number of other factors must also be taken into account, such as whether the costs outweigh the benefits or there is another solution that involves fewer costs but the same benefits (i.e. whether it is the most efficient solution).

Balancing costs, benefits and opportunities

As we just saw, practical reasoning involves weighing costs and benefits. For example, if you want to make a cup of tea, you decide that the costs (the effort to make tea) are outweighed by the benefits (drinking a cup of tea). In this case, however, you are almost certain that making tea will actually work. Opportunities therefore play no role in this. But suppose you are invited to a party while there is a chance that it will rain. If the costs of getting wet are the same as the benefits of going to the party, you also have to include the chance that it will or will not rain in your decision. In that case you can say that you should not go to the party unless the chance that it will rain is less than half the chance that it will not rain (so 1/3).

To calculate the expected value of an action, multiply the probability of that outcome by its value (the costs or benefits) for each possible outcome. Then you add all the calculations together to get the expected value. The action that yields the highest expected value is then the action that you must take. However, it is controversial to say that the rationality of all actions depends on their expected value; moral rules and ethics also play a role in many cases.

Statements as conclusions

As we saw in Chapter 1 (What are basic concepts about arguments?) ,we must distinguish arguments from explanations. Many arguments, however, have a statement as a conclusion. The purpose of the argument is that this and that is the cause of a fact or event. All these types of arguments start with an accepted fact, after which it is explained what caused that fact. An example of a common pattern of these types of arguments is:

If other possible causes cannot be completely excluded, we use words such as "probably not" and "almost always" in the premises, and "probably" in the conclusion.

Causal generalizations

When looking at causal relationships, correlation should not be confused with cause. For example, if you say that a high number of bicycles in a city is correlated with air pollution, it would not be correct to say that the high number of bicycles causes air pollution. In many such cases, there is an underlying factor that causes both states (in this case a high population). To establish a causal relationship, all other possible causes of an observation must be excluded.

Discount

If an argument contains conditional propositions, it often happens that we have to use a proposition twice in the reconstruction. However, we can shorten this proposition by using the number (P1, P2, etc.) of the proposition, as in the example below.

P1) It is warm outside

P2) Like (P1), many people wear shorts

C) Many people wear shorts

The purpose of argument reconstruction is to produce a clear and explicit version of the original argument of the writer/speaker. The argument will ultimately be in standard form.

How can arguments be judged? - Chapter 6

Rational persuasion

In the previous chapters we have seen that an argument is correct if the premises are true and the argument is deductively valid or inductively powerful. However, this does not always apply; often we cannot say for certain whether the premises are true. View the following example:

P1) Interest rates will not fall in the coming year and will not remain the same

C) Interest rates will rise in the coming year.

This argument is deductively valid, but it will not convince anyone of the conclusion unless the person has already accepted it. We call such an argument rationally unconvincing. Whether the argument is rationally convincing depends on the extent to which a particular person has been informed at a given time (in this case how much a particular person knows about the interest rates).

The following example shows another complication that can occur:

P1) Almost all cats have a tail

P2) Rambo is a cat.

C) Rambo probably has a tail.

This argument is inductively powerful. But suppose you know from personal experience that Rambo's tail is amputated. Others would reasonably assume that C is true, but you know it is not true. We then say that the argument for you has been defeated by other evidence that you have. However, this can only occur with inductive arguments.

We can state that an argument for a person is rationally convincing if it is 1) either deductively valid or inductively powerful, 2) the person reasonably believes that the premises are true, and 3) if it is not an inductively powerful argument that is defeated for the person in question. Below are a number of points that are important for rational persuasion.

1. It is not possible that the conclusion of a deductively valid argument is defeated by the total evidence of a person. After all, the definition of a deductively valid argument is that if the premises are true, the conclusion is necessarily true. By using words such as "likely" for the conclusion of an inductively powerful argument, it can happen that the premises are true but the conclusion false.
2. It is possible that an argument is rationally convincing for a person, but that it contains a false premise and is therefore incorrect. There are two types of mistakes that people can make: I) a reasonable error (accepting a false conclusion) and II) an unreasonable error (being convinced by bad reasons). For example, if you know as a doctor about a certain medicine that it has always worked with a certain disease in the past, it is reasonable to believe that this person will also work with the same disease in person X. If person X turns out to be sicker because of the medication, this is a type I error.
3. Attempts at rational persuasion must be distinguished from attempts at persuasion that do not claim to reason (but, for example, to emotions or prejudices).
4. Rational persuasion is not a matter of all or nothing, but a matter of degree.
5. Whether an argument is rationally convincing does not depend on whether you think it is. Sometimes we are not convinced by rationally convincing arguments, or we are convinced by rationally unconvincing arguments. There are three ways in which we can be mistaken about the rational persuasiveness of an argument. We can make mistakes that are related to whether an argument is valid or inductively powerful. Secondly, we may think that we have a good reason to accept a premise when this is not the case. Thirdly, we can make mistakes as to whether or not an argument is defeated for you.
6. Assessments of rational persuasiveness often depend on the assessment of authority behind certain propositions. For example, a proposition from a newspaper is more likely to be seen as rationally convincing than a proposition from a gossip magazine.

Some strategies for logical assessment

To judge whether an argument is deductively valid, you may ask yourself whether there is a situation where the premises are true, but the conclusion is false. If this is not the case, the argument is valid. If that is the case you have to ask yourself which situations are more likely; those in which the conclusion is true or those in which the conclusion is false. In the first case you can say that the argument is, at least to a certain extent, inductive.

If the conclusion of an argument is a generalization or a conditional proposition, the above method is not always easy to use. We can use conditional evidence for this. You first use the conclusion as ... then convert form. Here you assume that the premises are true (P) and that the antecedent of the conclusion (Q) is true. If (P) together with (Q) is true, the conclusion's conclusion is also true, and the argument is valid. For example the argument:

P1) Every midfielder in the Italian team is a good defender

P2) Every player who tackles well is a good defender

C) Every midfielder in the Italian team tackles well

If we convert the conclusion, this becomes: If someone is a midfielder with the Italian team (Q), he tackles well. This makes it easier to see that this argument is not valid.

Another way to see if an argument is valid is to imagine that the conclusion is not true. If it is impossible for the premises to be false, then the argument is valid. If it is still possible for the premises to be true, the argument is invalid (as in the example above).

Rejection by means of a counterexample

Using a counterexample is a useful way to see if an argument is valid. For example, consider this argument:

P1) Almost all heroin addicts were cannabis smokers before they became heroin addicts

C) Cannabis smokers often become heroin addicts

To show that this argument is invalid, we make the assumption explicit: "If almost everyone who does X did Y for that, then those who did Y become people who do X".

If you reconstruct the argument with Y = drink milk, you immediately see that this argument is invalid:

P1) Almost all heroin addicts drank milk before they became heroin addicts

C) Milk drinkers often become heroin addicts

Argument criticism - Avoiding "who says that ..."

Criticism of an argument sometimes focuses on a premise of which no one can say with certainty whether it is true or not. For example, the argument: "smoking causes an increased risk of lung cancer" is a frequently heard criticism: "Who says I will get lung cancer? Maybe I will stay healthy until I am eighty!". This is empty criticism, because the critic gives no reason to believe that he/she is less likely to suffer from lung cancer than others. To effectively criticize an argument one must demonstrate that 1) the argument is invalid or inductive, or 2) demonstrate that there is a reason not to believe one of the premises, or 3) that it is an inductive argument that defeats. is by another argument.

Another point to avoid with argument criticism is trying to invalidate it by sticking a label on it (for example, "politically correct" or "biased").

Argument commenting

When analysing arguments (consisting of argument reconstruction and argument assessment) it is sometimes useful to write a summary of this process. This summary consists of 1) The argument as originally formulated, 2) The argument in standard form and 3) A comment on the argument. This last step must in any case include the following points:

1. A general discussion of the argument, such as the context and structure of the argument.
2. A discussion of how and why the standard form reconstruction was done in this way, including any problems associated with it.
3. A discussion of the validity or degree of inductive power of the argument
4. A discussion and assessment regarding the truthfulness of the premises
5. In the case of an inductively powerful argument, indicate whether the argument was defeated for you personally.

In addition, when preparing a comment you have to consider how detailed it should be; this can differ per argument. It is important that the reconstruction is explained and justified in an informative, clear, not-rhetorical and balanced manner (neutral).

In the previous chapters we have seen that an argument is correct if the premises are true and the argument is deductively valid or inductively powerful. However, this does not always apply; often we cannot say for certain whether the premises are true.

How do you deal with fallacies and other erroneous reasoning? - Chapter 7

Fallacies

Fallacies (fallacys) are arguments that have the same form as the now known arguments, and yet there is something wrong with them. There is an inappropriate connection between the premises and conclusions. Fallacies can fall into two categories: formal fallacies and substantial fallacies. A logical error is made in the first category; the argument is therefore not deductively valid or inductively powerful. In the second category, the connection is based on very general unjustified assumptions or inferences. Various types of fallacies are discussed in more detail below.

Formal fallacies

1. Confirming the consequent of a conditional proposition. This occurs when we argue from the conditional premise that if P (the antecedent), then Q (the consequent) along with the premise that Q concludes that P. For example: If someone is a philosopher then that person is wise. Jan is wise, so Jan is a philosopher.
2. Denying the antecedent of a conditional proposition. This occurs when the conditional premise (if P then Q) together with the negation of the antecedent (not-P) draw the conclusion from the negation of the consistent (not-Q). For example: If someone is a philosopher (P), then that person is wise (Q). Jan is not a philosopher (not-P), so Jan is not a wise man (not-Q).
3. Deriving 'should' from 'being'. This happens when a prescriptive conclusion is derived from only a descriptive premise (s). For example: How can anyone say that the royal family should be abolished? The royal family has long been a central part of Dutch life.
4. The base rate fallacy. This occurs when we formulate an argument in the form of: a proportion of a characteristic of one group is higher than the proportion of that characteristic in another group. For example: Rex is either a cat or a rat. 75% of the cats are black, while only 45% of the rats are black. Rex is black, so Rex is probably a cat. This is incorrect, because the number of black rats can still be greater than the number of black cats.

Substantial fallacies

1. The fallacy of the majority. This occurs if we assume that it is true based on the majority believing something. Often this fallacy can be exposed by making the underlying premise explicit and applying it to another case. For example, if you have the following argument: Most highly educated people believe that the government should do more against crime, so the government should do more against crime. The underlying premise is; if most highly educated people think something is like that, it is like that. If you apply this to the argument "Most highly educated people think the earth is flat", you see the argument is wrong (Though these days there is a surprising number of people that would disagree with you on that).
2. Common practice. This fallacy is roughly the same as the previous one, but this is only a conclusion based on "what most people do".
3. Ad hominem . This fallacy comes in two forms; the first is when someone tries to attack an argument by attacking the person himself and the second is when someone rejects an argument because he does not like or reject the other person. Such as, “I won’t listen to a filthy whore like you”.
4. Ad hominem - circumstance. This is a subtype of the ad hominem trap. It happens when someone puts forward an argument in favour, after which the argument is attacked on the basis that that person would benefit from it (Of course you say that education needs to be improved, because you are a student yourself). However, this would mean that we should never accept an argument that would benefit the person making the argument, which of course is wrong.
5. Tu quoque. This fallacy is also about the connection we make between the suspected lack of credibility and the power of their argument. In Tu quoque , however, it is about inconsistency between the person's advice and his own actions. For instance; “Why should the police not allow me to drive faster than 120 on the highway? They also do it themselves, right?”. However, it is not a valid reasoning to say that an advice that someone gives is not valid if the person does not follow it himself.
6. Claim to authority. This fallacy exists when an argument makes an unjustified claim to authority. This can occur, for example, if the authority in question does not actually have authority for the case in question or if the authority is not sufficiently informed about the case.
7. The perfectionist trap. This occurs when we make excessive demands on an idea or proposal and then reject it because it does not completely solve the problem .
8. Assimilation of morality with legality. This occurs when we assume that everything that is legal is also moral and that everything that is illegal is also immoral. This does not always apply; for example, it is impossible to prohibit everything that is immoral (for example, lying in a relationship). There are also plenty of examples of things that were illegal but not immoral (for example, a ban on voting for women in the past).
9. Weak analogy. Analogies can be interesting and illustrative but are often unsuccessful. There is a trap if the analogy is too weak or if the analogy itself is not a good argument. For example: “It is nonsense to ban firearms. You can also kill someone with a hockey stick, but they aren't banned either, do you? ". This argument is incorrect; that X is similar to Y on a certain aspect does not mean that X and Y are the same in all aspects.
10. Causal fallacies. There are three types of this. The fallacy post hoc ergo propter hoc occurs if we incorrectly deduce that event X causes event Y just because Y occurred after X. The fallacy of confusing correlation with cause occurs if we incorrectly infer that just because X and Y (almost) always occur together (correlation), there is a causal relationship between the two. The reversal of cause and effect occurs if we incorrectly deduce that if XY causes, the absence of XY will occur. For example: If a lack of vitamin E (X) causes accelerated aging (Y), that does not mean that much vitamin E (absence of X) slows aging (occurrence of Y).
11. Epistemic fallacies. There are two types of this. The claim to ignorance occurs when we conclude that 1) something is not true because it is not proven (negative form) or that it is true because it is not proven that it is not true (positive form). The epistemic trap occurs if we incorrectly deduce that if someone believes P, then they should also believe Q because it is about the same thing or person. However, we cannot just assume that someone also knows that it is about the same person and therefore believes both P and Q.

Incorrect argumentation techniques

The following group of arguments are sometimes labelled as fallacies, but are not always invalid or inductive, or even incorrect. However, they are bad argumentation techniques and should be avoided. The different types of false argument techniques are explained below.

Ambiguity

This rhetorical technique arises when we deliberately use a word or words with the intention of confusing the public with the hope that the ambiguity will not be noticed. For example, consider the following argument, which is intended to undermine the idea of ​​universal human rights:

P1) In some countries men have the right to imprison their wives; in some countries men do not have that right.

C1) It is not true that people everywhere have the same rights at all times.

C2) The idea of ​​universal human rights is incorrect.

The ambiguity that is used here relates to the word "rights"; the idea of ​​universal human rights is about universal moral truths, while in P1 it is about what is permitted by law.

Red herring

This technique is about distracting the other from the core of the argument by distracting the person with something irrelevant. This is very similar to the rhetorical smokescreen technique, but an irrelevant premise is given as the reason for accepting the conclusion. Consider the following argument: "The judge should not make the verdict ‘guilty’ in the fraud case against company X. Company X is very popular with its shareholders and moreover makes a lot of profit". That the company is popular and profitable is irrelevant for the judge's judgment when it comes to whether or not the company has committed fraud. However, these types of arguments have a lot of potential to fool and convince the public.

Another common example of the red herring technique occurs if, in response to criticism from another party about its own approach to the problem, the criticism is rejected because it is not itself a solution to the problem.

The ability to recognize the red herring technique often depends on the knowledge you have about the subject in question.

The slippery slope

This technique is used if someone incorrectly assumes that allowing or prohibiting a particular course of action will inevitably lead to further related and undesired events. The rhetorical power of this technique is based on the fear of the unwanted events. An example is: "If cannabis is legalized, this will be the start of a downward spiral of abuse of hard drugs such as heroin". However, no good reasons are given for that downward spiral to actually follow; it only responds to the fear of abuse of hard drugs.

Straw man

This technique exists when someone ignores the actual position of the other and puts down a weaker version of that position through misinterpretation, exaggeration or simplification. This weaker version (the straw man) is then easier to knock down than the real argument.

Bypass the question

This technique exists when the truth of the conclusion is accepted by the premises, and the justice of the premises in turn depends on the truth of the conclusion. Consider the following example: Three thieves rob a bank. The first thief says: "I get the largest share, because I am the leader of our group." The second thief asks: "Who says you are the leader of the group?", To which the first thief answers, "I must be the leader, because I get the majority." This type of reasoning is also called circular reasoning.

False dilemma

This technique is the case when it is pretended that there are fewer alternatives than there actually are. Often someone states that there are only two options while there are actually more. For example, suppose someone asks you if you are in favour of positive discrimination against women in business. You say no, and the other draws the erroneous inference that you are against positive discrimination (while you may also be undecided), or even say that you are sexist.

Too much math

A final point of bad reasoning has to do with the incorrect interpretation of statistical material. One way in which this can occur is to confuse absolute and relative differences. Suppose an advertisement for a new medication states that the risk of a heart attack is reduced by 50% through the use of the medication. What many people do not realize is that this indicates the relative risk. However, this percentage is a percentage of the absolute risk. Suppose the absolute risk of a heart attack is 0.5, taking the medicine would reduce to 58% from 0.5, or 0.25. The effect now suddenly seems a lot less dramatic.

A second way in which incorrect interpretation of statistical material can occur has to do with the margin of error. A margin of error of 3%, for example with a poll before the elections, indicates that the poll predicts the actual percentage within 3% with a 95% chance of correctness. However, many people misinterpret the margin of error, as in the following example: “The poll for the upcoming elections puts party X 3% above party Y (50-47). That is within the margin of error of the poll, so there is actually a draw ”.

Fallacies (fallacys) are arguments that have the same form as the now known arguments, and yet there is something wrong with them. There is an inappropriate connection between the premises and conclusions. Fallacies can fall into two categories: formal fallacies and substantial fallacies. A logical error is made in the first category; the argument is therefore not deductively valid or inductively powerful. In the second category, the connection is based on very general unjustified assumptions or inferences. Various types of fallacies are discussed in more detail below.

What is the truth myth and what are philosophical directions? - Chapter 8

Truth and relativity

If we say something like, "The water is boiling", we express a conviction – a belief. A belief is an attitude that we adopt towards a proposition – a statement. A belief expresses that we believe a proposition, or we accept it as true. In fact, saying that a conviction is true is the same as pronouncing the proposition itself. Whether a proposition is true, however, depends only on whether the proposition is actually true and not on the person who says it is true. This seems simple, but it goes against a widely accepted myth that truth is relative. To disprove this myth, we must make a difference between different kinds of statements.

1. 1. If someone says, "Neptune is bigger than Venus," they use an assertory form. The fact that the person believes that the proposition is true does not mean that it is actually true. Whether the proposition is true or not depends solely on whether or not Neptune is actually larger than Venus.
   2. If someone says, "It's raining here", they use an indexical (here, that, this, they, today, etc.). An indexical is a word that indicates something specific, where what it indicates (in this case, where the speaker is located) is contextual. This also makes the truth content of the entire sentence contextual. Yet such sentences are still factual statements; when all relevant characteristics of the context have been established, we have a complete proposition with a fixed truthfulness.
   3. If person X says, "Math is difficult", that person makes an implicit relative claim. What the speaker means is that mathematics is difficult for him personally. A claim is implicitly relative if it sets a comparison or other relationship to something that is not explicitly mentioned. Since such sentences actually say something about the speaker while the sentence does not explicitly mention this, they are implicitly speaker relative.

When people seem to disagree about implicit speaker-relative sentences, they often compare this to actual factual disagreement. If person says X; "White chocolate is tastier than dark chocolate" and person Y says: "Pure chocolate is tastier than white chocolate", it may seem that person X and Y actually disagree. However, both people express different, not contradictory propositions, namely: 1) White chocolate tastes better for person X than dark chocolate and 2) Pure chocolate tastes better for person X than white chocolate. Person X and Y therefore do not actually disagree.

True for me, true for you

The myth that truth is relative is often erroneously reflected in discussions about factual matters, for example when someone says, "That's your opinion", or "Maybe that's true for you, but not for me". However, unless the topic of discussion is an implicit speaker-relative issue as described above, this is not a legitimate move. In discussions you must therefore pay close attention to whether the topic is about a preference, belief or other attitude, or about a factual statement. In the second case, there is no question of "true for you but not for me". So truth is not relative. It is objective, and the truth of a proposition is independent of our desire for or belief in its truth.

Truth, value and morality

In addition to the fact that many people think that truth is relative, we are often inclined to think that values as are relative in moral issues. In statements such as "euthanasia is immoral", disagreements about the truthfulness of such a statement are often seen as speaker-relative differences. It is not possible to prove that moral relativism is incorrect. There is, however, a good reason to be opposed to this. For example, suppose a terribly oppressive regime emerges in a certain country. The moral relativist cannot, however, hope or think that the regime is wrong; in his eyes it is a matter of preference (speaker-relative). Although this is an extreme example, it does show that moral relativism deprives us of the opportunity to rationally convince others of beliefs that may be harmful to others.

Theories

Just as people in a discussion often say that something is "just an opinion", you often hear the statement "that is just a theory". It seems as if theories are something subjective, while the term "theory" is precisely a way to distinguish scientific hypotheses from less valid and methodologically correct statements. A scientific theory proposes a hypothesis that can be tested by means of tests that can be performed in a perspective-free manner. The same principle applies to scientific explanations.

Conviction, justification and truth

It is not the case for every proposition that we either believe that it is true or believe that it is not true. Sometimes we take the position of a delayed judgment, for example because we believe that we do not have enough reason or evidence to accept something. It is also possible that a certain issue has never come to our attention and we therefore simply have no opinion about it. It is therefore important to remember that saying that if someone does not believe something, this is not the same as saying that someone does believe something. For example, if someone says, "I don't believe the minister is a bad person", they don't necessarily have to believe that the minister is a good person. He may not have enough information about the minister, or has he never thought about it.

So there are four positions that we can take against a proposition; believe, do not believe, postpone our judgment or not engage in the proposition. Believing and not believing are matters of moderation; for example, you may believe that the minister is a bad person to varying degrees. If someone has a certain belief, we may wonder if he is justified in having that belief; in other words, whether the argument he has for the conviction is rationally convincing for him. However, whether a belief is justified does not mean that the belief is actually true.

Justification without arguments

To be justified in having a certain belief it is not necessary to have an argument for the belief. An example of this is perception: when you see that your cat is lying on the bed, you are justified in thinking that the cat is lying on the bed. Another example is introspection; for example, if you feel hungry, happy or scared, you are justified in most cases to think that you do indeed feel hungry, happy or scared.

Knowledge

The truth of a belief is a necessary condition for being able to call that belief knowledge. However, it is not correct to say that the knowledge that something is so is the same as having a true belief. For example, suppose that someone who takes LSD every day has the hallucination that a friend's house is on fire. If one day it happens that the house of that friend is on fire, you cannot say that the LSD user knows that the house is on fire. A true belief only applies as knowledge if we arrive at that belief through the right route. We must therefore be justified in our conviction; we must have evidential support.

Failure of justification

There are two ways in which a belief may lack justification; it can either be genuine but inadequate or insincere.

Inadequacies

Suppose there are five suspects in a murder case, three men and two women. If you have no further evidence and person X says he believes the culprit was a man, the argument is somewhat rationally convincing to him (the chance of a man is greater than a woman). However, this is not sufficient justification; even if the culprit turns out to be a man, you cannot say that person X came up with his conviction through the right route. Person X is therefore not justified in his conviction. However, there is no precise limit for when our evidence support is sufficient to qualify as justified knowledge.

Errors related to justification

Sometimes the wrong assessment of the evidence leads to the formation of irrational beliefs, for example if we overestimate our evidence support. People often use this when convincing others incorrectly, for example, to give a few vivid examples as proof of generalization. Another form of irrational belief is when we allow ourselves to accept an incorrect belief if it benefits us. In such cases, we not only lack evidence, but we don't seem to care that we don't have evidence. This is the case, for example, if you believe that your terminally ill grandmother will get better, or that the predictions from your horoscope will become true.

Knowledge and rational persuasion

It is possible to have good reasons and therefore to be justified in keeping a false belief. However, rational persuasiveness does not require that the premises of an argument are actually true. Knowing, or having the knowledge, that an argument is correct therefore comprises more than rational persuasiveness; after all, we must be sure that the premises are true.

Even in the case of an inductively powerful argument, the degree of justice is not sufficient to equate the conclusion with knowledge. For example, if there are 51 white and 49 black stones in a bag, it is an inductively powerful argument that is rationally convincing to draw the conclusion that the stone you grab will be white. However, the argument is only a little inductively powerful and therefore does not count as knowledge, even if the stone you take turns out to be white.

Philosophical directions

Fundamentalism versus coherentism

As stated earlier, we usually do not find beliefs based on perception reasons or need arguments. So we see perceptual beliefs as self-justifying. It follows that we see other beliefs as ultimately based on perception. This vision is known as fundamentalism. However logical this vision may seem, there are also very logical arguments that contradict the vision. Perception is not always accurate; think of visual illusions, perceptual errors, dreams and hallucinations. The coherentism states that we are only justified in (perceptual or other) beliefs if it fits within our existing network of beliefs. For example, if a magician seems to saw a woman in two, that does not fit within our existing knowledge and thus we do not believe it.

Internal versus external justification

How can we justify perceptual beliefs? We can assume that if the person who has the belief functions normally and the perceptual circumstances are normal, then the belief is justified. But should the person in question not know that the circumstances are normal? The externalism suggests that beliefs are justified simply as they are produced correctly. The internal mechanism enables you should always be aware of the way of justification.

If we say something like, "The water is boiling", we express a conviction – a belief. A belief is an attitude that we adopt towards a proposition – a statement. A belief expresses that we believe a proposition, or we accept it as true. In fact, saying that a conviction is true is the same as pronouncing the proposition itself. Whether a proposition is true, however, depends only on whether the proposition is actually true and not on the person who says it is true. This seems simple, but it goes against a widely accepted myth that truth is relative. To disprove this myth, we must make a difference between different kinds of statements.