Passage Summary: When things aren't clear, people try to explain them in different ways, like how a famous quote about humans being the 'measure of all things' is understood differently by different people.

Conclusion: The lack of clarity in a statement or idea encourages people to provide their own explanations of its meaning.

Reasoning: A specific ancient proverb is provided as an example, showing that different groups of people have derived two distinct meanings from the same phrase.

Analysis: The sentence in question is the very first sentence of the stimulus. It functions as the main conclusion or the central thesis that the rest of the passage aims to illustrate. The author provides a specific example of a famous quote to show how its lack of clarity leads to various interpretations, thereby supporting the initial claim. Look for an answer choice that identifies this statement as the primary point the author is trying to establish.