Passage Summary: Apes can use human language but they don't use it to ask deep, philosophical questions. Therefore, the author concludes that only humans are capable of having philosophical thoughts.

Conclusion: Humans are the only species capable of philosophical thought.

Reasoning: Although apes can learn human language, they have never used it to ask philosophical questions about their own nature.

Analysis: The argument suffers from a significant 'Gap' between communication and cognition. It assumes that if a creature is capable of philosophical thought, it would necessarily express those thoughts through the human language skills it has acquired. We are looking for a Necessary Assumption that bridges this gap. Ask yourself: what if apes have philosophical thoughts but simply don't have the vocabulary to express them, or choose not to? The argument needs to assume that the absence of philosophical *speech* proves the absence of philosophical *thought*.