LR Necessary Assumption 2.3 Flashcards
Necessary rules
1) If I have it, the result COULD happen If I’m in the USA, I could be in New York
2) If I don’t have it, the result WON’T happen If I’m not in the USA, I won’t be in New York
What does the necessary assumption do?
Adds an unstated premise (evidence) that the argument needs to be true, or else it falls apart (does the author HAVE TO AGREE with my answer?)
Necessary question examples
1) Which one of the following is an assumption on which the argument depends?
2) The conclusion relies on which one of the following assumptions?
3) The argument presupposes which one of the following?
4) The conclusion doesn’t follow unless…
watch out for strong words: any, each, every, only, most in answers
Necessary assumption question I missed on 12/6/24
A recent study showed that the immune system blood cells of the study’s participants who drank tea but no coffee took half as long to respond to germs as did the blood cells of participants who drank coffee but no tea. Thus, drinking tea boosted the participants’ immune system defenses.
Level 5
Which one of the following is an assumption on which the argument depends?
A) All of the participants in the study drank either tea or coffee, and none drank both.
B) Coffee has no health benefits that are as valuable as the boost that tea purportedly gives to the body’s immune system.
C) In the study, drinking coffee did not cause the blood cell response time to double.
D) Coffee drinkers in general are no more likely to exercise and eat healthily than are tea drinkers.
E) Coffee and tea do not have in common any chemicals that fight disease in the human body.
Conclusion: Thus, drinking tea boosted the participants’ immune system defenses.
Test 143, Section 3, Question 19
Necessary assumption question I missed on 12/6/24
The populations of certain species of amphibians have declined dramatically in recent years, an effect many scientists attribute to industrial pollution. However, most amphibian species’ populations vary greatly from year to year because of natural variations in the weather. It is therefore impossible to be sure that the recent decline in those amphibian populations is due to industrial pollution.
Level 5
The argument depends on assuming which one of the following?
A) The amphibian species whose population declines have been attributed by many scientists to industrial pollution are not known to be among those species whose populations do not vary greatly as a result of natural variations in the weather. (pay attention to the double negatives, that’s why you missed this one)
B) The variations in amphibian species’ populations that result from natural variations in the weather are not always as large as the amphibian population declines that scientists have attributed to industrial pollution.
C) Either industrial pollution or natural variations in the weather, but not both, caused the amphibian population declines that scientists have attributed to industrial pollution.
D) If industrial pollution were reduced, the decline in certain amphibian populations would be reversed, and if industrial pollution increases, the decline in certain amphibian populations will be exacerbated.
E) If industrial pollution is severe, it can create more variations in the weather than would occur naturally.
Read carefully
Conclusion: It is therefore impossible to be sure that the recent decline in those amphibian populations is due to industrial pollution.
Test 143, Section 3, Question 25
