Jorge Luis Borges was a giant of 20th-century literature. As a librarian, essayist, and voracious reader in multiple languages, his own work was a vast web of literary and philosophical references. This quote isn't just a clever line; it's the core of his artistic identity. He believed that all writing is a form of re-reading and re-writing what has come before.

This quote is a cornerstone of literary thought in the Spanish-speaking world. It's a mantra for writers, students, and anyone who believes in lifelong learning. It serves as a powerful reminder that creativity doesn't happen in a vacuum—it's built on the foundation of others' ideas and stories.

The quote's power comes from its 'no... sino...' ('not... but rather...') structure. This is a common rhetorical device in Spanish that sharply contrasts two ideas to emphasize the second one. By placing 'lo que escribe' (what one writes) in opposition to 'lo que ha leído' (what one has read), Borges masterfully elevates the act of reading from a passive hobby to the defining act of an intellectual's existence.