Final answer:
The reasoning shown in the excerpt is moving from the big picture of hieroglyphics to the details of specific names and their translations.
Step-by-step explanation:
The type of reasoning shown in the excerpt is moving from the big picture of hieroglyphics being both representations of sounds and symbols to the details of Thothmes's and Ramesses's names. The author, Champollion, realizes the significance of the hieroglyphs in the names and how it provides insight into the entire system of hieroglyphic writing. This shows a logical progression from a general understanding to specific examples.
Learn more about Hieroglyphics and their significance