The notions of priority, foundation, and condition of possibility have been among the most pervasive themes in the history of philosophy. Yet philosophical traditions have largely focused on identifying particular foundations rather than examining the structure of priority itself. This paper introduces the concept of *Pre-Beingness* as an independent philosophical problem and investigates whether it is merely an epistemic presupposition or a more fundamental structure underlying being, cognition, and manifestation. Employing an analytical and argumentative method, and through a reexamination of ontological, epistemological, and phenomenological traditions, the study argues that structures of priority, grounding, referentiality, and conditionality recur throughout the history of thought. The findings suggest that Pre-Beingness is neither an entity, nor a mode of being, nor merely an epistemological category; rather, it is a meta-ontological structure that makes grounding, explanation, understanding, manifestation, and directedness possible. Accordingly, Pre-Beingness may be understood as the universal condition of priority relations and the common horizon within which philosophical foundations become intelligible.