Passage Summary: The author claims that science can't explain everything about why we do things because even if we knew every physical detail, we'd still feel like we don't truly understand the 'why' behind it.

Conclusion: Human behavior cannot be fully understood without investigating nonphysical aspects of people.

Reasoning: Even a perfect scientific description of the physical and environmental factors of an action would not provide a true understanding of why that action occurred.

Analysis: This argument is essentially circular; the author 'proves' that physical accounts are insufficient by simply asserting that they feel insufficient. There is a lack of objective evidence to support the claim that a complete physical account would leave us wanting more. When a speaker uses their own conclusion as the primary evidence for that conclusion, they are 'begging the question.' Look for an answer choice that points out how the author assumes the very point they are trying to prove, or fails to provide evidence beyond a mere assertion of their own perspective.