This dissertation presents a unified interpretation of Malebranche’s philosophical system that is based on his Augustinian theory of the mind’s perfection, which consists in maximizing the mind’s ability to successfully access, comprehend, and follow God’s Order through practices that purify and cognitively enhance the mind’s attention. I argue that the mind’s perfection figures centrally in Malebranche’s philosophy and is the main hub that connects and reconciles the three fundamental principles of his system, namely, his occasionalism, divine illumination, and freedom. To demonstrate this, I first present, in chapter one, Malebranche’s philosophy within the historical and intellectual context of his membership in the French Oratory, arguing that the Oratory’s particular brand of Augustinianism, initiated by Cardinal Bérulle and propagated by Oratorians such as Andre Martin, is at the core of his philosophy and informs his theory of perfection. Next, in chapter two, I explicate Augustine’s own theory of perfection in order to provide an outline, and a basis of comparison, for Malebranche’s own theory of perfection. In chapter three, I present Malebranche’s theory, along with showing its compatibility with his theory of divine illumination. In chapters four and five, I reconcile the mind’s ability to perfect itself with Malebranche’s strict occasionalism. In the end, I argue that Malebranche is not a full-blown occasionalist, but rather an instrumental occasionalist, which ultimately leaves metaphysical room for the mind to freely control its attention and produce its own attentive desires.