Passage Summary: A columnist argues that because people only donate to charity every once in a while, their generosity isn't a permanent part of their character.

Conclusion: The generosity shown by donating to charity is rarely a lasting character trait.

Reasoning: Most people who give to charity only do so on an occasional basis rather than constantly.

Analysis: The columnist is confusing how often someone does something with who they are as a person. It’s a bit like saying someone isn't a 'permanent' runner just because they aren't sprinting while eating dinner. The flaw lies in assuming that a virtue must be expressed through constant, non-stop action to be considered a permanent part of one's character. Look for an answer that highlights this confusion between the frequency of an act and the persistence of a trait.