In one of her most famous writings, Reply to Sor Philothea—written in response to a letter from the bishop of Puebla, who had posed as "Sor Philothea", which reprimanded her for neglecting religious literature—Sor (that is, Sister) Juana vigorously defended women's right to be educated and to take up intellectual pursuits, citing over forty women who had made significant contributions throughout history. Her reply incited harsh criticism from the Church. Although toward the end of her life Sor Juana renounced worldly learning, disposed of her library of 4,000 volumes (considered at the time to be the largest private library in Mexico), and devoted herself to penance, her story and reputation “as the first published feminist of the New World and as the most outstanding writer of the Spanish American colonial period” remain.
Many of her writings can be found online using the Sor Juana Inés de la Cruz Project.