5 Common Mistakes in Evaluating Premises

One section that I thought was interesting was Section D in Chapter 5 which talked about typical mistakes that can be found when evaluating ideas. The first common mistake is arguing backwards. This means that when presented with an argument, the listener believes that the argument sounds rational which leads to the conclusion being rational as well. On the contrary, an argument is supposed to sway us to think that the conclusion is plausible, not that the idea is not true at all. The second common mistake is confusing a possibility with plausibility. Simply enough, individuals tend to confuse the difference between a possible argument and a plausible argument which are two completely different things. A possible argument has the chances that it could be false while a plausible argument is credible and rings true. The third mistake is bad appeals to authority. This means that because people see others accepting a particular idea, they automatically accept it as well without thinking the argument through. The fourth mistake is mistaking the person for the claim. In other words, an individual disregards an idea simply because it came from a person who they might not see as reliable. Finally, the fifth common mistake is mistaking the person for the argument. This mistake is similar to the fourth common mistake, however, instead of rejecting the claim, individuals reject the argument that the unreliable individual makes.

Organizational Communication

One topic that I found interesting was organizational communication which can be found in the Essential Guide to Group Communication text. Because there are millions of organizations throughout the world, organizational communication is key to having a successful group. Organizational communication is the process that “involves the exchange of messages between organizational members or among members of different organizations” (Wiemann 54). Organizational communication rules and norms are valid when certain group members are communicating with one another group of members. The reason behind this is because it is then much easier for all individuals involved to be able to communicate the correct message from one another. The main reason why individuals want to have good organizational communication is because it allows all individuals involved to become successful in whatever task they are trying to take on. Additionally, it is extremely helpful for individuals to fully understand the group that they are trying to communicate with because it brings down all of the barriers that are holding the group back from succeeding to their fullest potential.

Structure of Arguments

2. I am on my way to school (1). I left five minutes late (2). Traffic is heavy (3). Therefore, I’ll be late for class (4). So I might as well stop and get breakfast (5).

Argument: Yes

Conclusion: Should not rush to school because there is heavy traffic so might as well get breakfast.

Additional premises needed? Instead of rushing to school and missing class, might as well take your time and relax. Rushing will not only stress an individual out, but it will cause a chaotic mess as well.

Identify any subargument: Sentences 2 and 3 support sentence 4. Sentences 2, 3, and 4 support sentence 5.

Good argument? I think that this is a good argument, however, it could be better. However,

I think that this exercise was alright. It certainly was not one of my favorite assignments, however, it was not as bad as it could have been. It was useful because I had to take a part an argument and this exercise made me do that.

Content Fallacies

Bad appeal to common belief is one of the many content fallacies that can be found in Epstein’s text. The overall meaning of this fallacy is that the reason why most people do something, even if it is bad, is because they see others doing it which causes them to think that it is acceptable to do the same. Since the action is believed to be acceptable, society carries on with their daily life performing that action without any guiltily feeling left at the end of the day. One example that can be seen just about every day is swearing. Swearing under any circumstance is not okay, however, the majority of the population swears on a daily basis. Because everyone swears, society automatically thinks that it is alright for them to do the same. However, most people take serious offense to this because they see it as a disrespectful way to talk to someone.

Tests for an Argument to Be Good

According to Epstein, there are three tests an individual must take in order to claim that an argument is good. They are the following:


1. The idea is both reasonable and believable.
2. The idea is more believable than the conclusion.
3. The argument is either valid nor strong, not both.

An example would be that I had heard a rumor at work that if I taught over 300 kids in the swim lesson program this year, I would get a five dollar an hour raise. After hearing this, I had worked extremely hard trying to not only do my best teaching the children I had on a regular basis, but trying to get the word out that I was a good instructor hoping to be requested. By the end of the year, I had taught about 320 kids in the program which qualified me to getting the five dollar an hour raise.

This argument would follow the first test because the idea is both reasonable and believable because my boss is extremely generous to her employees. The second test is not possible for the idea to be true and the conclusion to be false because I had heard from other employees that it had happened to them in the past (but they could have gotten the raise for another reason). And finally, the third test defines the argument to be valid because it was based on a rumor started by other employees and not stated by my boss.

Strong versus Valid Arguments

A strong argument can be defined as a statement that has an accurate idea but also has an inaccurate conclusion. An ideal strong argument would have an accurate idea and inaccurate conclusion that occur at the same time as one another. A valid argument is when the accurate idea and inaccurate conclusion cannot be applied at the same time. In other words, there is no promising way for the idea and the conclusion to be false at the same moment. Epstein believes that a strong argument is better than a valid argument that ends with the same conclusion.


An example of a strong argument would be that the blue books that many students use for an exam in a class are not always blue. They can usually be found in green or yellow. This would be a strong argument because the idea is true and the conclusion is false. An example of a valid argument would be that the blue books that many students use for an exam in a class are never blue. They can only be found in green or yellow. This is an example of a valid argument because neither the idea nor the conclusion are false at the same time; there are blue books that are actually blue, however, they are not as common.

Plausible and Implausible Claims

In the text, Epstein talks about plausible and implausible claims. Plausible claims can be defined as when an individual has a very good reason to believe that the point that is being made is true and valid. An example of a plausible claim would be that little girls love the color pink. This would be a plausible claim because young girls are taught that the color pink is associated with girls resulting in them loving the color pink and anything and everything that comes in that shade. An implausible claim, otherwise known as a dubious claim, is a claim that leaves an individual to feel like there is no way that the point being made is true and valid. An example of this would be that cats bark. This statement is completely not true because cats do not bark. This statement would be a perfect example because everyone knows that cats do not bark which completes the definition of an implausible claim.

Descriptive and Prescriptive Claims

Descriptive and prescriptive claims are two concepts that Epstein talks about in his text. A descriptive claim is when the statement is clear and to the point. An example of this would be that it is illegal to be in a car without having your seatbelt fastened. This statement would be a descriptive claim because it is saying exactly what it means with no way of getting around it. On the other hand, a prescriptive claim is a statement that is not as obvious as a descriptive claim, but recommends how something ought to be. For example, Jane should wear her seatbelt when she is sitting in the car even if she is not the driver. This is a prescriptive claim because it is recommending Jane to do something rather than commanding her to do it. Another concept that ties in with prescriptive claims is value judgment. A value judgment is when individuals should do or choose to do the right thing in the particular situation that they might be in rather than choosing or doing what is wrong and dishonest. This would be described as a perspective claim because the individual is doing what they should do.

Subjective Claims and Objective Claims

Subjective claims are statements that are based upon personal opinions that reflect how the individual or group of individuals “think, believe, or feel” (Epstein 20). One of my friends and I are planning an event and we were discussing centerpieces and decorations. Since the theme of the event is a tea party, I had pictured a simple, small bouquet of pretty flowers that would go along with the garden theme while my friend imagined a bigger center piece. I told her that the big centerpiece would fit well because, in my opinion, large centerpieces are for evening events indoors while our event was during the day and outdoors. This would be a subjective claim because I told her my opinion about her idea and although it was a good idea, I believe it wasn’t the right look we were going for.


On the other hand, objective claims are statements that do not convey opinions but give specifics. Because objective claims state “impersonal standards,” they focus on events and facts (Epstein 20). Another example could be seen in the event that my friend and I are planning. A few days ago, we were making a list with everything that we needed to order and one of the items on the list was tables. We decided that we needed about twenty tables so that the guests at the event would be able to have a place to sit and have their tea. This would be an objective claim because it is stating a simple fact, not an opinion or belief.