PrepTest 120, Section 4, Question 4
The purpose of the physical sciences is to(60 more words not shown)
Which one of the following(6 more words not shown)
- ASuccessful predictions of(10 more words not shown)
- BOne cannot predict(17 more words not shown)
- CIn some cases,(18 more words not shown)
- DThe goal of(13 more words not shown)
- EThe methods used(14 more words not shown)
Reading the argument
Predicting what someone will do isn't necessarily the same as understanding why they do it. Consider the contrast with a falling apple. We can predict how it will fall without asking what the apple hopes to accomplish. Human actions raise a different question: what is the person trying to achieve? The author says understanding an action requires knowing that goal.
What we’re looking for
At first, this can read like a collection of observations about science and people. The main-conclusion question is a reason to go back and find which claim gets support. The word “for” helps: successful predictions don't provide understanding, for understanding requires knowing the action's goal. The goal requirement explains the claim just before it. So that's the main point to look for: successfully predicting human behavior does not, by itself, amount to understanding it. The discussion of physical science sets up the contrast, and the requirement about goals gives the reason.
Working the answers
- ACorrect
This restates the claim supported by the requirement about goals. We might predict an action successfully and still lack the knowledge needed to understand it. The author uses the difference between prediction and understanding to make that point about human behavior.
- B
This says we cannot predict behavior without knowing the person's purpose. That's not what the passage says. Knowing the goal is required for understanding, while successful prediction can fall short of understanding. B moves the requirement from understanding to prediction and erases the distinction the author is making.
- C
The author doesn't say successful prediction constitutes understanding in the physical sciences. We are told that prediction is their purpose. Treating those two ideas as equivalent would add a claim, even if it seemed plausible to us. C also leaves out the specific conclusion about predictions of human behavior.
- D
This is the opening background statement. It introduces what physical science aims to do so the author can compare it with predictions about people. The later reasoning doesn't try to establish this description of science; it supports the claim that predicting human behavior doesn't provide an understanding of it.
- E
This again puts a requirement on prediction. The passage requires knowledge of a goal to understand an action, not necessarily to predict the action. We shouldn't turn E into an unstated fact just because psychological states sound relevant to human behavior. It neither restates the main conclusion nor follows from the stated requirement.
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