The article explores the relation between philosophy and science in Roman Ingarden. It examines whether philosophical refection provides a foundational basis for scientific activity, and, if so, what is the nature and scope of that basis. The essay begins analyzing the internal structure and organization of knowledge according to Ingarden. It then turns to the relation between ontology and science, emphasizing the presence of an ontological foundation for scientific inquiry. Ingarden’s views on the possibility of a transcendental foundation and the broader role of transcendental inquiry in philosophy are then addressed. Central to this analysis is Ingarden’s emphasis on epistemology as the exclusive domain of transcendental considerations, along with an exploration of the connections between epistemology and scientific knowledge. Finally, the essay identifies textual passages in which Ingarden seems to depart from the phenomenological postulate of philosophizing without pre-judgments, offering a nuanced critique of his approach.