Weakening Arguments

Overview

Identify the conclusion and reasons for the conclusion when asked to weaken or strengthen an argument, and select the answer that affects these.

The local agriculture commission conducted a survey of local irrigated soybean crops. While ordinarily, over-irrigated or under-irrigated crops have a lower crop yield, in the survey, over-irrigated soybean fields saw the excess water simply drain away from the field unless the field was such that this drainage was inhibited. It follows that farmers need not worry about over-irrigating their soybean crop unless there is currently no way for excess water to drain.

Which one of the following, most weakens the conclusion that farmers need not worry about over-irrigating?

(A) Agriculturalists do not currently understand all the risks associated with over-irrigation. (B) Over-irrigation is not as harmful to crops already without adequate drainage for the water. (C) Excessive irrigation can cause a field with adequate drainage to eventually have inadequate drainage. (D) All productive soybean crops need to be irrigated to some extent. (E) Any excess irrigation will ultimately drain away from a soybean field over a period of time.

The conclusion of the argument is that farmers whose fields have adequate drainage don't have to worry about over-irrigating soybean fields. The reason for this is that excess water always drains away. Choice (C) weakens this conclusion because it demonstrates that, even if the excess water drains away, this excess water might inhibit the ability of excess water to drain from the field in the future.

In weakening or strengthening arguments, the key concept is “relevance.” The correct response will make the conclusion more or less likely. 4.03 Weakening & Strengthening Arguments

Practice

1. Many people refrain from eating any animal products. But most people who do not eat meat will still consume dairy products, eggs, and other foods made from part of an animal as long as this does not involve hurting the animal. The production of dairy products, however, involves inhumane things such as capturing an animal and forcing labor upon it, as do eggs and invariably any other animal product. Therefore, most people who do not eat meat are still prolonging inhumane things to be inflicted on animals.

Which one of the following most strengthens the argument that most people who do not eat meat are still prolonging inhumane treatment of animals?

(A) People who consume things, the production of which involves inhumane treatment of animals, are invariably assuring the continued existence such inhumane behavior. (B) Inhumane treatment of animals would be substantially reduced if a large fraction of the population refrained from eating animal products like eggs. (C) The primary reason that people refrain from eating meat is to stop the inhumane treatment of animals. (D) The majority of people who eat meat also eat other animal products such as dairy and eggs. (E) There are few people who wish to abandon eating all products produced by animals entirely.

2. Mozart’s opera “The Magic Flute” tells the story of a hero who finds himself in a faraway land, one which in many productions is reminiscent of ancient Egypt. Indeed, at the beginning of Act II, the people in the faraway land sing a hymn to the Egyptian deities Osiris and Dionysus. Because the hymn sounds much like the German hymns of Mozart’s time, some musicologists argue that Mozart’s opera was poking fun at contemporary religion.

Which one of the following, if true, would most weaken the conclusion that Mozart was ridiculing contemporary religion?

(A) The monarchy and clergy under whom Mozart lived imposed severe punishments for ridiculing religion or the national church. (B) Many modern pieces of musical theater satirize contemporary cultural elements such as religion. (C) Many people who lived in Mozart’s time would not have found it funny to ridicule the church or religion. (D) Other operas written by Mozart contained satire of contemporary society, but not of religion. (E) “The Magic Flute” pokes fun at many controversial things, and many modern versions of it omit sections that seem sexist or racist.

Comments

Answers to Practice Questions

1. (A)

Choice (A) states a principle which demonstrates that people who consume things which impel a result are invariably furthering that result. When applied to these facts, this principle means that eating dairy products prolongs animal suffering.

2. (A)

The argument's conclusion is that Mozart was making fun of religion. The rationale for this is the similarities between a hymn in Mozart's work and contemporary religious hymns. Choice (A) weakens this because it gives a reason why poking fun at religion at the time of Mozart would have been implausible.