Final answer:
The 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' and Ramesses' names.
Step-by-step explanation:
The 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' and Ramesses' names. The excerpt states that Champollion realized the significance of the hieroglyphs in these names and how they provided insight into the entire system of hieroglyphic writing. This indicates that Champollion started with the general understanding of hieroglyphics and then focused on the specific examples of the names to gain a deeper understanding of the system.