Israel is not safe if Iran gets nuclear missiles since Iran has threatened multiple times to destroy Israel and if Iran had nuclear missiles it would be able to carry out this threat. Moreover, since Iran has been developing enriched uranium, they have the key component needed for nuclear weapons—every other part of the process of building a nuclear weapon is simple compared to that. Therefore, Israel is not safe. Since all professional hockey players are missing front teeth and Martin is a professional hockey player, it follows that Martin is missing front teeth.

And since almost all professional athletes who are missing their front teeth have false teeth, it follows that Martin probably has false teeth.

Anyone who eats the crab rangoon at China Food restaurant will probably have stomach troubles afterward. It has happened to me every time, which is why it will probably happen to other people as well. Since Bob ate the crab rangoon at China Food restaurant, he will probably have stomach troubles afterward. Albert and Caroline like to go for runs in the afternoon in Hyde Park. Since Albert never runs alone, we know that any time Albert is running, Caroline is running too.

But since Albert looks like he has just run since he is panting hard , it follows that Caroline must have ran too. Paraphrases of premises or conclusions are sometimes needed in order to make the standard form argument as clear as possible. A paraphrase is the use of different words to capture the same idea in a clearer way. There will always be multiple ways of paraphrasing premises and conclusions and this means that there will never be just one way of putting an argument into standard form.

In order to paraphrase well, you will have to rely on your understanding of English to come up with what you think is the best way of capturing the essence of the argument. Again, typically there is no single right way to do this, although there are certainly better and worse ways of doing it. What is the conclusion of this argument? Think about it before reading on. This statement seems to capture the essence of the main conclusion in the above argument. The premises of the argument would be: 1.

So here is the reconstructed argument in standard form: 1. To illustrate this, I will give a second way that one could accurately capture this argument in standard form. Here is another way of expressing the conclusion: We do not know that Jeremy killed Tim.

That is clearly what the above argument is trying to ultimately establish and it is a much simpler in some ways conclusion than my first way of paraphrasing the conclusion. However, it also takes more liberties in interpreting the argument than my original paraphrase.

So how shall I paraphrase the premises that support this conclusion? Here is another way of paraphrasing the premises and putting the argument into standard form: 1. Therefore, we do not know that Jeremy killed Tim. I have taken quite a few liberties in interpreting and paraphrasing this argument, but what I have tried to do is to get down to the most essential logic of the original argument.

The paraphrases of the premises I have used are quite different from the wording that occurs in the original paragraph. Nonetheless, this reconstruction seems to get at the essence of the logic of the original argument.

As long as your paraphrases help you to do that, they are good paraphrases. Being able to reconstruct arguments like this takes many years of practice in order to do it well, and much of the material that we will learn later in the text will help you to better understand how to capture an argument in standard form, but for now it is important to recognize that there is never only one way of correctly capturing the standard form of an argument.

And the reason for this is that there are multiple, equally good, ways of paraphrasing the premises and conclusion of an argument. Unfortunately, there is no simple way to answer this question. The only answer is that you must rely on your mastery and understanding of English in order to determine for yourself whether the paraphrase is a good one or not.

Validity So far we have discussed what arguments are and how to determine their structure, including how to reconstruct arguments in standard form. But we have not yet discussed what makes an argument good or bad.

The central concept that you will learn in logic is the concept of validity. Validity relates to how well the premises support the conclusion, and it is the golden standard that every argument should aim for. A valid argument is an argument whose conclusion cannot possibly be false, assuming that the premises are true. Another way of putting this is as a conditional statement: A valid argument is an argument in which if the premises are true, the conclusion must be true.

Here is an example of a valid argument: 1. Violet is a dog 2. All that matters for validity is whether the conclusion follows from the premise. And we can see that the conclusion, Violet is a mammal, does seem to follow from the premise, Violet is a dog.

That is, given the truth of the premise, the conclusion has to be true. We can illustrate this with another example, where the premises are clearly false: 1.

Everyone born in France can speak French 2. Barack Obama was born in France 3. Therefore, Barack Obama can speak French from This is a valid argument. Because when we assume the truth of the premises everyone born in France can speak French, Barack Obama was born in France the conclusion Barack Obama can speak French must be true.

Notice that this is so even though none of these statements is actually true. So we have a valid argument even though neither the premises nor the conclusion is actually true.

That may sound strange, but if you understand the concept of validity, it is not strange at all. Remember: validity describes the relationship between the premises and conclusion, and it means that the premises imply the conclusion, whether or not that conclusion is true. George was President of the United States 2.

Therefore, George was elected President of the United States from 1 This argument is invalid because it is possible for the premise to be true and yet the conclusion false. Here is a counterexample to the argument.

In other words, it is possible for the premise of the argument to be true and yet the conclusion false. And this means that the argument is invalid. If an argument is invalid it will always be possible to construct a counterexample to show that it is invalid as I have done with the Gerald Ford scenario. A counterexample is simply a description of a scenario in which the premises of the argument are all true while the conclusion of the argument is false. If you can construct a counterexample to an argument, the argument is invalid.

To apply the informal test of validity ask yourself whether you can imagine a world in which all the premises are true and yet the conclusion is false. If you can imagine such a world, then the argument is invalid.

If you cannot imagine such a world, then the argument is valid. It will help to better understand the concept of validity by applying the informal test of validity to some sample arguments. Joan jumped out of an airplane without a parachute 2. Therefore, Joan fell to her death from 1 To apply the informal test of validity we have to ask whether it is possible to imagine a scenario in which the premise is true and yet the conclusion is false if so, the argument is invalid.

So, can we imagine a world in which someone jumped out of an airplane without a parachute and yet did not fall to her death? Think about it carefully before reading on. As we will see, applying the informal test of validity takes some creativity, but it seems clearly possible that Joan could jump out of an airplane without a parachute and not die—she could be perfectly fine, in fact. All we have to imagine is that the airplane was not operating and in fact was on the ground when Joan jumped out of it.

If that were the case, it would be a true that Joan jumped out of an airplane without a parachute and yet b false that Joan fell to her death. Thus, since it is possible to imagine a scenario in which the premise is true and yet the conclusion is false, the argument is invalid. Joan jumped out of an airplane traveling mph at a height of 10, ft without a parachute 2.

Joan fell to her death from 1 Is this argument valid? You might think so since you might think that anyone who did such a thing would surely die. But is it possible to not die in the scenario described by the premise? For example, maybe someone else who was wearing a parachute jumped out of the plane after them, caught them and attached the parachute-less person to them, and then pulled the ripcord and they both landed on the ground safe and sound.

Or maybe Joan was performing a stunt and landed in a giant net that had been set up for that purpose. Or maybe she was just one of those people who, although they did fall to the ground, happened to survive it has happened before. All of these scenarios are consistent with the information in the first premise being true and also consistent with the conclusion being false. Thus, again, any of these counterexamples show that this argument is invalid. Notice that it is also possible that the scenario described in the premises ends with Joan falling to her death.

And that means that the argument is not valid i. Obama is President of the United States. Kenya is not in the United States. Therefore, Obama was not born in Kenya from In order to apply the informal test of validity, we have to ask whether we can imagine a scenario in which the premises are both true and yet the conclusion is false.

Can you imagine such a scenario? You cannot. The reason is that if you are imagining that it is a true that a person can be President of the United States only if they were born in the United States, b true that Obama is president and c true that Kenya is not in the U.

Thus we know that on the assumption of the truth of the premises, the conclusion must be true. And that means the argument is valid. In this example, however, premises 1, 2, and 3 are not only assumed to be true but are actually true. However, as we have already seen, the validity of an argument does not depend on its premises actually being true. Here is another example of a valid argument to illustrate that point. A person can be President of the United States only if they were born in Kenya 2.

Obama is President of the United States 3. Therefore, Obama was born in Kenya from Clearly, the first premise of this argument is false. And this means that the argument is valid. We cannot imagine a scenario in which the premises of the argument are true and yet the conclusion is false. Rather, validity depends only on the logical relationship between the premises and the conclusion.

In the next section we will address this topic. Exercise 5: Determine whether or not the following arguments are valid by using the informal test of validity. If the argument is invalid, provide a counterexample.

Katie is a human being. Therefore, Katie is smarter than a chimpanzee. Bob is a fireman. Therefore, Bob has put out fires. Gerald is a mathematics professor. Therefore, Gerald knows how to teach mathematics. Monica is a French teacher.

Therefore, Monica knows how to teach French. Bob is taller than Susan. Susan is taller than Frankie. Therefore, Bob is taller than Frankie. Craig loves Linda. Linda loves Monique. Therefore, Craig loves Monique. Orel Hershizer is a Christian. Therefore, Orel Hershizer communicates with God. All Muslims pray to Allah. Muhammad is a Muslim. Therefore, Muhammad prays to Allah. Some protozoa are predators.

No protozoa are animals. Therefore, some predators are not animals. Charlie only barks when he hears a burglar outside. Charlie is barking. Therefore, there must be a burglar outside. Soundness is defined in terms of validity, so since we have already defined validity, we can now rely on it to define soundness. A sound argument is a valid argument that has all true premises.

That means that the conclusion of a sound argument will always be true. But if the premises are actually true, as they are in a sound argument, then since all sound arguments are valid, we know that the conclusion of a sound argument is true. Compare the last two Obama examples from the previous section.

While the first argument was sound, the second argument was not sound, although it was valid. The relationship between soundness and validity is easy to specify: all sound arguments are valid arguments, but not all valid arguments are sound arguments. Although soundness is what any argument should aim for, we will not be talking much about soundness in this book. The reason for this is that the only difference between a valid argument and a sound argument is that a sound argument has all true premises.

But how do we determine whether the premises of an argument are actually true? Well, there are lots of ways to do that, including using Google to look up an answer, studying the relevant subjects in school, consulting experts on the relevant topics, and so on.

But none of these activities have anything to do with logic, per se. The relevant disciplines to consult if you want to know whether a particular statement is true is almost never logic!

Since this is a logic textbook, however, it is best to leave the question of what is empirically true or false to the relevant disciplines that study those topics. And that is why the issue of soundness, while crucial for any good argument, is outside the purview of logic.

For a deductive argument to fail to do this is for it to fail as a deductive argument. Tweets is a healthy, normally functioning bird 2. Most healthy, normally functioning birds fly 3. Therefore, Tweets probably flies Given the information provided by the premises, the conclusion does seem to be well supported.

That is, the premises do give us a strong reason for accepting the conclusion. This is true even though we can imagine a scenario in which the premises are true and yet the conclusion is false. For example, suppose that we added the following premise: Tweets is 6 ft tall and can run 30 mph.

Were we to add that premise, the conclusion would no longer be supported by the premises, since any bird that is 6 ft tall and can run 30 mph, is not a kind of bird that can fly. That information leads us to believe that Tweets is an ostrich or emu, which are not kinds of birds that can fly.

As this example shows, inductive arguments are defeasible arguments since by adding further information or premises to the argument, we can overturn defeat the verdict that the conclusion is well-supported by the premises. Inductive arguments whose premises give us a strong, even if defeasible, reason for accepting the conclusion are called, unsurprisingly, strong inductive arguments.

In contrast, an inductive argument that does not provide a strong reason for accepting the conclusion are called weak inductive arguments. Suppose that instead of saying that most birds fly, premise 2 said that all birds fly. Tweets is a healthy, normally function bird.

All healthy, normally functioning birds can fly. Therefore, Tweets can fly. This is true even if we add that Tweets is 6 ft tall because then what we have to imagine in applying our informal test of validity is a world in which all birds, including those that are 6 ft tall and can run 30 mph, can fly. Although inductive arguments are an important class of argument that are commonly used every day in many contexts, logic texts tend not to spend as much time with them since we have no agreed upon standard of evaluating them.

In contrast, there is an agreed upon standard of evaluation of deductive arguments. We have already seen what that is; it is the concept of validity. In chapter 2 we will learn some precise, formal methods of evaluating deductive arguments. There are no such agreed upon formal methods of evaluation for inductive arguments.

This is an area of ongoing research in philosophy. In chapter 3 we will revisit inductive arguments and consider some ways to evaluate inductive arguments. In such a case, we can supply the premise s needed in order so make the argument valid.

Making missing premises explicit is a central part of reconstructing arguments in standard form. We have already dealt in part with this in the section on paraphrasing, but now that we have introduced the concept of validity, we have a useful tool for knowing when to supply missing premises in our reconstruction of an argument.

In some cases, the missing premise will be fairly obvious, as in the following: Gary is a convicted sex-offender, so Gary is not allowed to work with children. Gary is a convicted sex-offender 2. Therefore, Gary is not allowed to work with children from 1 However, as stated, the argument is invalid. Before reading on, see if you can provide a counterexample for this argument. That is, come up with an imaginary scenario in which the premise is true and yet the conclusion is false.

Here is just one counterexample there could be many : Gary is a convicted sex-offender but the country in which he lives does not restrict convicted sex-offenders from working with children. We can and should state that premise explicitly in our reconstruction of the standard form argument.

The obvious one is that no sex- offenders are allowed to work with children, but we could also use a weaker statement like this one: Where Gary lives, no convicted sex-offenders are allowed to work with children. It is weaker because it is not so universal in scope, which means that it is easier for the statement to be made true.

For more on strong and weak statements, see section 1. So here is the argument in standard form: 1. Gary is a convicted sex-offender. Where Gary lives, no convicted sex-offenders are allowed to work with children. Therefore, Gary is not allowed to work with children. As we can see from this example, a missing premise is a premise that the argument needs in order to be as strong as possible. Typically, this means supplying the statement s that are needed to make the argument valid.

But in addition to making the argument valid, we want to make the argument plausible. When it comes to supplying missing premises, this means supplying the most plausible premises needed in order to make the argument either valid for deductive arguments or inductively strong for inductive arguments.

Although in the last example figuring out the missing premise was relatively easy to do, it is not always so easy. Here is an argument whose missing premises are not as easy to determine: Since children who are raised by gay couples often have psychological and emotional problems, the state should discourage gay couples from raising children. Children who are raised by gay couples often have psychological and emotional problems.

Therefore, the state should discourage gay couples from raising children. However, as it stands, this argument is invalid because it depends on certain missing premises. The conclusion of this argument is a normative statement— a statement about whether something ought to be true, relative to some standard of evaluation. Normative statements can be contrasted with descriptive statements, which are simply factual claims about what is true.

That is, it is simply a claim about what is in fact the case in Russia today. An important idea within philosophy, which is often traced back to the Scottish philosopher David Hume , is that statements about what ought to be the case i.

This is known within philosophy as the is-ought gap. The problem with the above argument is that it attempts to infer a normative statement from a purely descriptive statement, violating the is-ought gap.

We can see the problem by constructing a counterexample. Suppose that in society x it is true that children raised by gay couples have psychological problems. However, suppose that in that society people do not accept that the state should do what it can to decrease harm to children.

In this case, the conclusion, that the state should discourage gay couples from raising children, does not follow. Thus, we can see that the argument depends on a missing or assumed premise that is not explicitly stated.

That missing premise must be a normative statement, in order that we can infer the conclusion, which is also a normative statement. There is an important general lesson here: Many times an argument with a normative conclusion will depend on a normative premise which is not explicitly stated. The missing normative premise of this particular argument seems to be something like this: The state should always do what it can to decrease harm to children. Thus, we can reconstruct the argument, filling in the missing normative premise like this: 1.

The state should always do what it can to decrease harm to children. In order to show this, we just have to imagine a scenario in which both the premises are true and yet the conclusion is false. Here is one counterexample to the argument there are many. In this case, even if it were true that the state should always do what it can to decrease harm to children, it does not follow that the state should discourage gay couples from raising children. For example, it could be that the reason that children of gay couples have higher rates of psychological problems is that in a society that is not yet accepting of gay couples, children of gay couples will face more teasing, bullying and general lack of acceptance than children of heterosexual couples.

In that case, the state should not necessarily discourage gay couples from raising children. But for the government to discourage black Americans from raising children would have been unjust, since it is likely that if there was a higher incidence of psychological and emotional problems in black Americans, then it was due to unjust and unequal conditions, not to the black parents, per se.

Thus, one way of making the argument at least closer to valid would be to add the following two missing premises: A. The rate of psychological problems in children of gay couples is higher than in children of heterosexual couples. The higher incidence of psychological problems in children of gay couples is not due to any kind of injustice in society, but to the fact that the parents are gay.

Their addition makes the argument much stronger, but making them explicit enables us to clearly see what assumptions the argument relies on in order for the argument to be valid. This is useful since we can now clearly see which premises of the argument we may challenge as false. The important lesson from this example is that supplying the missing premises of an argument is not always a simple matter.

In the example above, I have used the principle of charity to supply missing premises. Mastering this skill is truly an art rather than a science since there is never just one correct way of doing it cf.

Exercise 6: Supply the missing premise or premises needed in order to make the following arguments valid. Try to make the premises as plausible as possible while making the argument valid which is to apply the principle of charity.

Ed rides horses. Therefore, Ed is a cowboy. Tom was driving over the speed limit. Therefore, Tom was doing something wrong. If it is raining then the ground is wet. Therefore, the ground must be wet. All elves drink Guinness, which is why Olaf drinks Guinness. Instead, he invited his friend Alexia.

So he must like Alexia more than me. The watch must be broken because every time I have looked at it, the hands have been in the same place. Olaf drank too much Guinness and fell out of his second story apartment window.

Therefore, drinking too much Guinness caused Olaf to injure himself. Mark jumped into the air. Therefore, Mark landed back on the ground. Therefore, as of , the United States was still a racist nation. The temperature of the water is degrees Fahrenheit. Therefore, the water is boiling. Capital punishment sometimes takes innocent lives, such as the lives of individuals who were later found to be not guilty. Therefore, we should not allow capital punishment.

Allowing immigrants to migrate to the U. Therefore, we should not allow immigrants to migrate to the U. However, before answering the assessment tests, the participants signed an online informed consent form explaining this study this means that they clicked on the acceptance box authorizing their voluntary collaboration with the research.

Assessment tests 2. The items can be classified into two dimensions: critical openness this dimension is composed of 7 items and reflective skepticism this dimension is composed of 4 items. Responses are coded using a Likert scale ranging from 1 meaning "strongly disagree" to 5 meaning "strongly agree".

The Spanish version of Bravo et al. No specific instrument for this purpose adapted to Spanish was found. For this purpose, we used the revision of the PATCAT by Wilson, White and Obst , which also contemplates that further adaptations to other healthcare contexts can be derived. The Spanish adaptation with all psychometric properties will be addressed in another manuscript. However, Table 1 specifies the changes we made in the items. Responses were coded with a graduated scale ranging from 1 "strongly disagree" to 7 "strongly agree".

It was originally developed by Spielberger, Gorsuch and Lushene The STAI measures the degree of anxiety from two perspectives and dimensions: 1 trait-type anxiety it has 20 items and state-type anxiety this dimension also has 20 items.

In this version, the validity and reliability indices of both forms of the STAI were excellent. Psychology professionals should be able to advise their clients about Los profesionales de la salud deben ser capaces de asesorar a sus clientes sobre los commonly used complementary therapeutic methods. A number of complementary and alternative approaches hold promise for Una serie de enfoques complementarios y alternativos son prometedores para el the treatment of psychological conditions.

Complementary therapies can be dangerous in that they may prevent Las terapias complementarias pueden ser peligrosas, ya que pueden impedir que las people from obtaining proper treatment. La terapia complementaria representa un enfoque confuso y mal definido. Complementary medicine is a threat to public health. Thinking Skills and Creativity 42 dimension assessing state-type stress was applied.

This type of stress refers to variable anxiety dependent on the circumstances experienced by the subject this type does not represent a personality trait. This was chosen because it was intended to measure and know the stress levels of the physicians contextualized within the situation of the coronavirus crisis. In fact, order to facilitate statistical inferences regarding the scores of this scale, the Spanish scores transformed to percentiles was used as a reference.

Specifically, the 80th percentile was used as the threshold. It aims to assess the cognitive ability to discriminate between pseudoscientific information fake news and scientifically proven information related to the coronavirus.

Participants had to specify by means of 3 response alternatives whether the content of each item possessed or lacked scientific evidence. The response alternatives were the following: "yes" the content is scientifically proven and true , "? Each time the participant chose the correct answer, one point was added.

In total, there were 18 items. Procedures The design of this research was correlational and was based on the application of different surveys and online assessment tests. Data collection was conducted between November and May The sampling had the same duration as the second state of alarm in Spain, which started on November 9, and ended on May 9, Access or collection of the sample was performed through two forms of contact: 1 Direct methods.

In this case, physicians who were active in the practice of internal medicine and emergency medicine were contacted directly by email. Physicians were also contacted directly by cell phone, and questionnaires were sent by WhatsApp. On other occasions, face-to-face meetings were held with the participating physicians to explain the full scope of this research and thus stimulate their involvement. In this type of strategy, the researcher did not have direct contact with the physicians and sought the help of intermediaries.

The main intermediaries were the following: a medical students who were performing internships and had direct contact with the physicians in their department, b administrative staff of the healthcare centers including orderlies in Fig. Bar graphs based on physician proportions for each measured dependent variable score. In the state-type stress graph yellow color and the total CTDS score graph green color , not all percentages could be included due to a lack of space.

These percentages are only an orientation. Thinking Skills and Creativity 42 the case of hospital centers , c nonmedical healthcare staff e. This generated an online viral chain effect that facilitated the dissemination of the survey. In order to detect false positives i. These control categories were "studying medicine" and "I am a nonmedical health professional". All participants who checked this category answered the questionnaires, but their data were not incorporated in this study to avoid generating noise in the raw data matrix.

A total of cases that checked one of these boxes were discarded. Descriptive statistics were calculated for the variables measured, and several multiple regression models were tested. The regression models aimed to determine which variables predicted stress levels and the ability to detect fake news for the physicians.

Parameter estimation was performed using the residual least squares procedure. This method is recommended in statistics to fit parsimonious and ecological models when working with multiple predictor variables. In this way, the estimates of the explained variance and forecasts would be more consistent, and possible false positives would be avoided.

Results 3. Graphical description of the variables and measures of central tendency The distribution of the scores of the variables measured is shown in Fig.

The bar graphs are based on percentages to facilitate the interpretation and visibility of the data. Descriptive statistics for the entire sample and for each physician group or category are given in Tables 2 and 3 provide the descriptive statistics separating the participants by autonomous community.

Results in Tables 2 and 3 indicated that the means between groups were not different from each other for most of the dependent variables. For the other combinations of means and variables, no significant differences were observed. This means that internists and emergency physicians had similar levels of critical thinking and were subjected to the same equivalent levels of stress. Multiple regression analysis As a preliminary step to the regression, Table 4 shows the linear correlations between the variables.

As seen in Table 4, there were very high correlations that suggest the possibility of linearly combining a regression. The variables were set considering the evidence provided by the authors cited in the introduction Bago et al.

Minimum and maximum Internist Intensive care Physicians with other Total values values physician physician specialties Critical Openness 7—35 Thinking Skills and Creativity 42 Table 3 Descriptive statistics means and standard deviations of the variables measured according to the Spanish communities. Table 4 Matrix of the correlations between variables for the purpose of applying multiple regression models.

Critical openness — 2. Reflective skepticism 0. Total critical thinking scores 0. Skeptical Attitude toward alternative therapies 0. Ability to detect fake news 0. Correlations that were considered to fit the regression models are highlighted in bold.

Stress levels and the ability to detect fake news were specified as criterion variables. While many psychosocial interventions used in social work practice have strong research evidence supporting their efficacy, a surprising number do not, potentially resulting in harmful outcomes. In this book, the authors cast a critical eye on the reality of commonly used scientific and pseudoscientific practices in social work today.

Psychology: The Science of Mind and Behaviour is here with a new, fully updated and revised third edition. This book examines pseudoscience from a variety of perspectives, through case studies, analysis, and personal accounts that show how to recognize pseudoscience, why it is so widely accepted, and how to advocate for real science. Gorman, David H. Gorski, David K. Herreid, Jonathan Howard, Seth C. Willis, Corrine Zimmerman. Download Conspiracy Theories books , Conspiracy theories are a part of the human condition.

Everyone believes at least one, but given the number of conspiracy theories, it is more likely that everyone believes a few. Some people have a worldview defined by them. Conspiracy theories are just another reminder that people disagree about many things, including truth. These disagreements have always existed and always will. We have to live with conspiracy theories and with the people who believe them. The only way to do this is have compassion and tolerance for others, and to hold our own beliefs to high standards.

This book introduces students to the research into conspiracy theories and the people who propagate and believe them. In doing so, it addresses the psychological, sociological, and political sources of conspiracy theorizing Uscinski rigorously analyzes the most current arguments and evidence while providing numerous real-world examples so students can contextualize the current debates.

Each chapter addresses important current questions, provides conceptual tools, defines important terms, and introduces the appropriate methods of analysis.