Final answer:
The first quatrain of Edmund Spenser's 'Sonnet 75' suggests that nature's power is greater than that of human efforts, as seen through the erasure of a name written on the sand by the sea.
Step-by-step explanation:
The central idea of the first quatrain in Edmund Spenser’s Sonnet 75 is that nature is stronger than human creations. This is expressed through the speaker’s attempt to immortalize his love by writing her name on the sand, only for the waves to erase it. This act highlights the futility of trying to defy the natural order and the impermanence of human efforts against the relentless force of nature. The quatrain serves to set up a conflict that is then explored throughout the sonnet, contrasting the temporal physical world with the potential for eternal life through art and poetry.