LSAT Explanation PT 35, S1, Q18: The current pattern of human consumption

LSAT Question Stem

Which one of the following is an assumption required by the argument? 

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is B. 

LSAT Question Complete Explanation

First, let's break down the argument in the passage:

Premise: There is only so much metal ore available (a nonrenewable resource).

Subconclusion/Premise: Ultimately, we must either do without or turn to renewable resources to replace metal ore.

Conclusion: The current pattern of human consumption of resources, in which we rely on nonrenewable resources like metal ore, must eventually change.

Think of this argument like a simple example: imagine you have a limited number of cookies in a jar. Once those cookies are gone, you either have to do without cookies or find a different snack to replace them. As a result, you'll have to change your snacking habits.

An "Evaluate" question for this argument could be: "Can nonrenewable resources be indefinitely replaced by other nonrenewable resources?"

Now, let's discuss each answer choice for the question, which is a Necessary Assumption question:

a) There are renewable resource replacements for all of the nonrenewable resources currently being consumed.

This answer choice is not necessary because the passage acknowledges that we may have to "do without" some resources. The argument doesn't assume that there are renewable replacements for all nonrenewable resources.

b) We cannot indefinitely replace exhausted nonrenewable resources with other nonrenewable resources.

This is the correct answer choice. If we could indefinitely replace nonrenewable resources with other nonrenewable resources, there would be no need to change our consumption habits. The argument assumes that this is not possible, which is why we must turn to renewable resources or do without.

c) A renewable resource cannot be exhausted by human consumption.

The argument doesn't assume that renewable resources can never be depleted. It only suggests that we should turn to renewable resources as an alternative to nonrenewable resources. Even if renewable resources could be exhausted, the argument still holds that our consumption habits must change.

d) Consumption of nonrenewable resources will not continue to increase in the near future.

The argument doesn't make any assumptions about consumption patterns in the near future. It only discusses what must eventually happen due to the limited availability of nonrenewable resources.

e) Ultimately we cannot do without nonrenewable resources.

This answer choice actually goes against the argument, as it suggests that we must have nonrenewable resources. The argument states that we must eventually change our consumption habits, either by turning to renewable resources or doing without nonrenewable resources. Therefore, this answer choice is incorrect.