In 1664, at age sixteen, Sor Juana Inés de la Cruz was sent to live in Mexico City. She asked her parents' permission to disguise herself as a male student so that she could enter the university. Not being allowed to do this, she continued her studies privately. She came under the tutelage of the Vicereine (wife of the Viceroy Antonio Sebastián de Toledo) Leonor Carreto. The viceroy, wishing to test her learning and intelligence (she being then seventeen years old), invited several theologians, jurists, philosophers, and poets to a meeting, during which she had to answer, unprepared, many questions, and explain several difficult points on various scientific and literary subjects. The manner in which she acquitted herself astonished all present, and greatly increased her reputation. Her literary accomplishments soon made her famous throughout Nueva España.
In her poem Redondillas she defends a woman's right to be respected as a human being. Therein, she also criticizes the sexism of the society of her time, poking fun at and revealing the hypocrisy of men who publicly condemn prostitutes, yet privately pay women to perform on them what they have just said is an abomination to God. Sor Juana asked: "Who sins more, she who sins for pay? or He who pays for sin?" This was no idle view, as this was especially dangerous because the Counter Reformation was raging. Anyone who challenged societal values and ecclesiastical dogma could be investigated by the Spanish Inquisition on suspicion of heresy.
In response to her critics, Sor Juana wrote a letter entitled Respuesta a Sor Filotea (Reply to Sister Filotea), in which she defended women's right to education. In response, the Archbishop of Mexico joined other high-ranking officials in condemning Sor Juana's "waywardness". In defense of her right to engage in intellectual activity, Sor Juana identifies in the Respuesta a Sor Filotea a genealogy of women intellectuals—including such diverse examples as Hypatia of Alexandria (370–415), Saint Gertrude the Great (1256–1311), and Queen Christina of Sweden—and argues that humanistic and scientific pursuits are compatible with theology and necessary for its comprehension.
Sor Juana Inés de la Cruz was said to have been a true enlightenment personality, knowledgeable in theology, philosophy, astronomy, mathematics, literature, painting and music. Matters came to a head in 1690, when a letter was published attacking Sor Juana's focus on the sciences, and suggesting that she should devote her time to soft theology.
Thus there can be no question: Sor Juana Inés de la Cruz suffered gender discrimination. Times haven't changed very much.