60% sureLots of sources credit Sor Juana Inés de la Cruz with this, and they agree with each other. The book or the speech it first came from hasn't turned up yet.
What turned up
Respuesta a sor Filotea (1691), her own sentence: 'Lo que sólo he deseado es estudiar para ignorar menos'. The English here expands it with an antithesis absent from the original — a paraphrase, not a translation
Sources checked
she-philosopher.comChecked using claude-sonnet-5, 20 August 2026confirms Respuesta (1691) context and names Margaret Sayers Peden's 1982 translation, though this exact line's text wasn't retrievable there