The Discourses, a work attributed to the ancient Stoic philosopher Epictetus, is believed to have been compiled from Epictetus’s lectures by his student Arrian. Some claim that Arrian himself authored The Discourses and falsely attributed authorship to Epictetus. That is, however, highly unlikely. Epictetus’s views were well known by his contemporaries in Roman society; if Arrian tried to pass off his own views as Epictetus’s, this deception would soon be exposed.

Summarize Argument

The author concludes that the claim that Arrian wrote The Discourses and falsely attributed the work to Epictetus is highly unlikely. He supports this by saying that Epictetus’s views were widely known, so if Arrian had tried to pass off his own views as Epictetus’s, the deception would have been quickly exposed.

Notable Assumptions

The author assumes that there was a clear and easily identifiable distinction between the views of Epictetus and Arrian, which would make any attempt to falsely attribute the work apparent. He also assumes that Epictetus’s contemporaries could have exposed the deception publicly and that that exposure would still be known today. Finally, he assumes that there aren’t any other reasons that may have motivated Arrian to falsely attribute The Discourses to Epictetus.

A
The Discourses would have received very little attention in Roman society if that work had not been attributed to Epictetus.

This weakens the argument by suggesting that Arrian may have been motivated to falsely attribute The Discourses to Epictetus in order for the work to receive more public attention.

B
Some of the philosophy that modern scholars believe Arrian subscribed to can be found in The Discourses.

This doesn’t strengthen the argument because, whether Arrian wrote The Discourses and falsely attributed it to Epictetus or just compiled his teacher’s lectures, it makes sense that some of Arrian’s own philosophy would be in the work.

C
Arrian in some ways modeled himself on the historian Xenophon, who had written works that he falsely attributed to the philosopher Socrates.

The fact that Arrian modeled himself in some ways on a historian who falsely attributed works to a famous philosopher does not strengthen the argument. We don’t know which of Xenophon’s ideas or practices Arrian adopted.

D
Arrian had high status in Roman society, which he knew would be undermined if he were shown to be dishonest.

This strengthens the argument by giving another reason why Arrian likely wouldn’t have falsely attributed The Discourses to Epictetus. Arrian’s high status would be damaged if he were seen as dishonest, and it’s reasonable to assume he wouldn’t want that.

E
During his long career, Arrian was a soldier, a consul of Rome, and a governor in Turkey.

This fails to address whether or not it is likely that Arrian falsely attributed The Discourses to Epictetus. Arrian’s various positions throughout his long career are not relevant to the argument.


8 comments

A study tested the performance of 70 pilots, half of whom chose to go on a reduced-calorie diet. Those who did not diet performed well, while pilots who were dieting performed worse, although they had performed well before they started their diets. The average level of impairment for the dieters was approximately equal to that caused by consuming two alcoholic drinks on an empty stomach.

"Surprising" Phenomenon
Pilots who dieted performed worse than pilots who didn’t diet.

Objective
Since this is an “Except” question, the correct answer won’t help explain the results of the study. In other words, we won’t learn why caloric deficit has such a strong impact on pilots.

A
Dieters often become preoccupied with worries about their weight losses and calorie intakes.
The dieting pilots were more concerned about their weight loss than about flying their planes properly. This certainly contributes to an explanation.
B
Many of the pilots, including both dieters and nondieters, consumed alcohol before the tests, and dieting increases vulnerability to alcohol’s effects.
For whatever reason, many of the pilots in the test had a couple drinks beforehand. The dieters couldn’t handle their liquor, hence their reduced performance.
C
Reduced-calorie dieting makes most people more vulnerable to irritability and fatigue.
The dieting pilots got tired during the test, hence their poor performance.
D
Many of the pilots chose to go on the diet because they were curious about whether one’s weight affects one’s piloting skills.
We’re not interested in why the pilots chose to diet. We’re interested in why dieting effects piloting, which this doesn’t explain.
E
Whereas alcohol has no effect on the level of glucose (a nutrient vital to brain function) in the bloodstream, dieting lowers the glucose level.
The dieters were lacking a nutrient vital to proper cognition. Their flying abilities suffered accordingly.

10 comments

Guam has 40 times more spiders than nearby islands have. Biologists argue that this is a consequence of the accidental 1940s introduction into Guam of the brown tree snake, which by the 1980s had eliminated ten of twelve native bird species. The biologists attribute the spider population’s increase to the loss of bird species, because many birds prey on spiders and some use spiderwebs in constructing nests.

Summarize Argument: Phenomenon-Hypothesis
The biologists hypothesize that the spider population’s increase is a result of the introduction of the brown tree snake. This is based on the fact that the brown tree snake eliminated native bird species, and on the subsidiary conclusion that this loss of bird species caused the spider population to increase. This sub-conclusion is based on the fact that many birds prey on spiders and use spiderwebs to construct nests.

Notable Assumptions
The author assumes that there’s no other explanation for the increase in spider population on Guam besides the decrease in bird species. The author also assumes that there was a decrease in overall bird population (as opposed to simply a decrease in the number of species, which doesn’t automatically indicate a decrease in population).

A
Birds compete with spiders for insect prey.
This strengthens by providing another causal mechanism that could show bird populations can affect spider populations. If birds and spiders compete for food, a decrease in birds would mean spiders have less competition for food. This could help spiders survive and thrive.
B
The biologists counted spiderwebs as a means of estimating the spider population.
This has no clear impact on the hypothesis. So, we estimated the spider population increase based on an increase in the number of spiderwebs. Does the spider population have anything to do with a decline in birds? (B) is silent on this.
C
Spiderwebs are more prevalent on Guam than on nearby islands.
This doesn’t help connect the increase in spiders with the bird population decline. The issue is the cause of the spider population increase, not whether the spider population has increased. We already know Guam has more spiders than other nearby islands.
D
The two bird species remaining on Guam have proliferated since the arrival of the brown tree snakes.
This undermines the argument by pointing out that overall number of birds might have increased even if the number of species has gone down.
E
Brown tree snakes have proven difficult to eradicate on Guam.
This has nothing to do with whether the snakes caused the bird population to decline and whether the bird population decline caused an increase in spider population. We care about the effect of the snakes. Not how easy it is to remove the snakes.

30 comments

If a novelist is popular he or she can vividly imagine large numbers of characters, each with a personality and attitudes that are completely different from those of the others and from those of the novelist. Such a writer also will be capable of empathizing with people who have goals completely different from his or her own and so will have some doubts about the genuine value of his or her own desires.

Summary
If a novelist is popular, then he or she can vividly imagine large numbers of characters with different personalities and attitudes. A popular novelist is also capable of empathizing with people who have different goals, and will have some doubts about the genuine value of his or her own desires.

Notable Valid Inferences
For MBT-Except questions, the wrong answers are all Could Be True. The one right answer Must Be False.
Some novelists who can vividly imagine large numbers of characters with different attitudes and personalities have doubts about the genuine value of their own desires.
Some novelists who can vividly imagine large numbers of characters are not popular novelists.

A
Some novelists who can vividly imagine large numbers of characters with attitudes and personalities completely different from those of the others are not popular.
Could be true. We know that all popular novelists can vividly imagine large numbers of characters, but it is possible that some novelists who are not popular can also do this. A necessary condition can always occur without the sufficient condition.
B
Some novelists are incapable of empathizing with people whose goals are completely different from their own.
Could be true. We know that all popular novelists are capably of empathizing with people whose goals are different, but it is possible that some novelists who are not popular are incapable of this. A necessary condition can always occur without the sufficient condition.
C
Some people who lack the ability to empathize with those who have goals completely different from their own are popular novelists.
Must be false. As shown below, this answer choice completely contradicts one of our conditions. If an author is a popular novelist, then that novelist must have the ability to empathize with those who have completely different goals.
D
No people who have doubts about the value of their own desires are incapable of empathizing with people who have goals that are completely different from their own.
Could be true. We know all people capable of empathizing with those who have completely different goals have doubts about the value of their own desires. It is also possible that people who have doubts about the value of their own desires are also capable of empathizing.
E
Most writers who have doubts about the value of what they desire are popular novelists.
Could be true. We know that all popular novelists have doubts about the value of their own desires. It is also possible that most writers who have these doubts are popular novelists.

9 comments