“How to get at the basis of Hartmann’s ontology? Let us sketch the superstructure, and then descend into the depths of the foundation. Besides the two primary spheres, there are two secondary spheres of being — the spheres of ‘logic’ and ‘knowledge’. These are mid-way spheres inasmuch as they share the categories of both the primary spheres. (Compare Whitehead’s ‘hybrid’ entities.)
Following the Aristotelian tradition, Hartmann takes ontology as the science of beings as beings. Ontology is concerned with what first makes beings beings. The word “Sein” gives rise to the illusion, as if there is some entity or attribute corresponding to it, something over and above, may be, underlying or pervading the various beings. Hartmann rejects this thought. A science of beings as beings is not a science of any such entity or attribute as Sein. On the other hand, it can only be a science which lays bare the various spheres of being along with their general and special categories and inter-categorial (hence, inter-sphere) relations. Hence, ontology becomes a doctrine of categories, a “Kategorienlehre”. To keep these primary and secondary spheres along with their general and special categories before the mind, in their distinctions as well as in their interrelations, is essential for an understanding of Hartmann’s ontology. Hartmann displays great acumen in drawing these distinctions and in keeping clearly apart what he considers to be distinct. Through these distinctions, he claims to have the clue in hand for avoiding many of the errors of the traditional ontologies.
There are two primary spheres of being: the real and the ideal. The real consists of the chain of temporal events. The structure of the real sphere is a stratification of various levels: the material, vital, psychical and spiritual. The stratification consists in the relation of “founding”. The higher level is “founded” on the lower. The lower provides the basis for the higher. The real sphere has its general categories, those which determine the entire sphere, irrespective of the differences of strata. Such categories are, for example, the modal categories. But each stratum of reality has also its own special categories. The relation in which two levels of reality stand to each other is concretely illustrated in the relation in which the categories of the The key to this entire discussion lies in the formulation of the nature of the ideal sphere. In setting aside what he calls the errors of tradition, Hartmann shows here his capacity at its best.” pp. 116-117.
From: Jitendra Nath Mohanty. Phenomenology and ontology. The Hague: Martinus Nijhoff 1970 – Chapter XI. A recent criticism of the foundations of Nicolai Hartmann’s ontology – pp. 115-128.