The paper contends that abstraction lies at the core of the philosophical and methodological rupture that occurred between Husserl and his mentor Franz Brentano. To accomplish this, it explores the notion of abstraction at work in these two thinkers' methodological discussions through their respective claims regarding the structure of consciousness, and shows that how Husserl and Brentano analyze the structure of consciousness conditions and strictly delineates the nature and reach of their methods of inquiry. The paper pays close attention to intentionality, founding (Fundierung), and qualitative modification (qualitative Modifikation) understood as principles of consciousness. While intentionality has been the topic of numerous discussions surrounding these two thinkers' work, founding and qualitative modification have slipped under the radar despite the fact that they hold—as I intend to show—the key to shedding new light on their respective methods of inquiry. More specifically, the paper explicates the ways in which Brentano's notion of founding (understood as a relationship between whole acts) and his failure to identify radical-qualitative modification as a principle of consciousness preclude him from offering a successful model for philosophical universalizing thought. It is my hope to show that Husserl's rethinking of founding as a relationship between certain structural moments of acts along with his novel notion of qualitative modification ground his attempt to carve a new method of philosophical inquiry—albeit jejune and ambiguous at the time of the Investigations, yet nevertheless able to successfully negotiate the problems faced by his predecessor.