Final answer:
The Nymph declines the Shepherd's offer because she sees the gifts and promises as temporary and understands the importance of lasting values over fleeting pleasures. Additionally, parallels with Sylvia's story show a deep loyalty to nature, leading to the refusal to betray its secrets.
Step-by-step explanation:
The Nymph refuses the Shepherd's invitation for several reasons. In 'The Nymph's Reply to the Shepherd' by Walter Raleigh, the nymph responds to the shepherd's promises with a sense of realism, noting that the pleasures he offers are all temporary - they will 'soon break, soon wither, soon forgotten.' Her decision reflects an understanding that the shepherd's promises of love and material delights are transient, and not enough to build a lasting commitment. Also, in other related texts, loyalty to nature, as illustrated by the narrative of Sylvia and the white heron, plays a crucial role in the characters refusing to betray the secrets of the natural world. Sylvia cannot speak of the heron's location because her experience with the creature and the forest has instilled in her a sense of duty to protect the wildlife around her. This loyalty overrides any temptation to yield to human desires or material gain.