Heidegger defines regional ontology as a specific determination of being founded upon a general theory of being, such as science (Naturwissenschaften). In most cases not made explicit, the ontology of science is guided by a specific form of understanding of being that scientists work with in their field. For example, the understanding of being in physics differs from that in epidemiology. There are therefore regions within the regional ontology of science itself. Each of these regions is worthy of its own phenomenological investigations.