Final answer:
Husserl's phenomenology focuses on how consciousness structures experience rather than proving the external world's existence, providing foundational understanding for sciences. This approach clarifies the a priori concepts and categories that underlie empirical knowledge.
Step-by-step explanation:
Edmund Husserl's contribution to phenomenology offers an alternative to proving the external world's existence as Descartes did. Husserl suggested we should examine consciousness itself and how objects appear in our conscious experience. His phenomenological method requires us to suspend assumptions about objects and instead scrutinize our conscious experience of them.
This introspection is meant to provide a firm, indubitable foundation for sciences by focusing on the direct experience before scientific abstraction. Such a focus on the immediate experience ensures that the sciences are built upon the way consciousness structures and interprets the world, which for Husserl is more certain than positing an independent external reality.
Moreover, Husserl's insights help in understanding the preconditions that make science possible. The examination of consciousness can illuminate those a priori categories and concepts that are the framework within which empirical knowledge operates. It is the understanding of these foundational elements of thought and perception that phenomenology seeks to clarify, providing a deeper basis for all sciences to build upon.