LSAT Explanation PT 34, S3, Q17: Zoologist: Animals can certainly signal each

LSAT Question Stem

Which one of the following is an assumption on which the zoologist's argument depends? 

Logical Reasoning Question Type

This is a Necessary Assumption question. 

Correct Answer

The correct answer to this question is D. 

LSAT Question Complete Explanation

First, let's analyze the argument in the passage. The zoologist states that animals can signal each other with sounds and gestures (premise). However, this does not confirm the thesis that animals possess language, because it does not prove that animals possess the ability to use sounds or gestures to refer to concrete objects or abstract ideas (conclusion). The argument structure relies on the connection between using sounds or gestures to refer to concrete objects or abstract ideas and the possession of language.

To make this more understandable, let's use a simple example. Imagine a group of people using hand gestures to communicate. Just because they can communicate using hand gestures doesn't necessarily mean they possess a full-fledged language, as they may not be able to convey complex ideas or refer to specific objects using these gestures.

The "Evaluate" question for this argument would be: "Does the ability to use sounds or gestures to refer to concrete objects or abstract ideas determine whether animals possess language?"

Now, let's discuss the answer choices for the question, which is a Necessary Assumption question. We need to identify the assumption on which the zoologist's argument depends.

a) Animals do not have the cognitive capabilities to entertain abstract ideas.

- This answer choice is not necessary for the argument, as it focuses on the cognitive capabilities of animals, rather than the connection between referring to concrete objects or abstract ideas and possessing language.

b) If an animal's system of sounds or gestures is not a language, then that animal is unable to entertain abstract ideas.

- This answer choice is also not necessary, as it focuses on the ability to entertain abstract ideas, not the ability to refer to concrete objects or abstract ideas using sounds or gestures.

c) When signaling each other with sounds or gestures, animals refer neither to concrete objects nor abstract ideas.

- This answer choice may seem tempting, but it doesn't address the connection between referring to concrete objects or abstract ideas and possessing language. It only states what animals do when signaling each other.

d) If a system of sounds or gestures contains no expressions referring to concrete objects or abstract ideas, then that system is not a language.

- This is the correct answer. It establishes the necessary connection between the ability to use sounds or gestures to refer to concrete objects or abstract ideas and the possession of language. If this assumption is not true, the argument falls apart.

e) Some animals that possess a language can refer to both concrete objects and abstract ideas.

- This answer choice is not necessary for the argument, as it only talks about some animals that possess language, rather than establishing the connection between referring to concrete objects or abstract ideas and possessing language.

In conclusion, the correct answer is D, as it establishes the necessary connection between the ability to use sounds or gestures to refer to concrete objects or abstract ideas and the possession of language, which is crucial for the zoologist's argument.