In Being and Time, Martin Heidegger made the distinction between ontical and ontological. Ontical refers to a particular area of Being, whereas ontological ought torefer to Being as such. The history of ontology in Western philosophy is, in Heidegger's terms, properly speaking, ontical, and ontology ought to designate fundamental ontology. He says "Ontological inquiry is indeed more primordial, as over against the ontical inquiry of the positive sciences". It is from this distinction he developed his project of fundamental ontology
Background
The project of fundamental ontology appeared as a result of Heidegger's decision to re-interpret phenomenology, which he had developed earlier in collaboration with his mentor Edmund Husserl, using a neat set of ontological categories. For this project Heidegger had to look for new terminologies by means of which it would become possible for him adequately to represent the structure of his new brand of phenomenology. The significantly large change in terminology Heidegger made in the project also resulted in a reconsideration and redefinition of many traditional concepts. For instance, the thesis that a phenomenon is the essence of a thing could not be articulated by using traditional concepts alone; in fact, Heidegger consistently refused to use these concepts in their original senses. He re-interpreted such basic philosophical categories as "subject", "object", "spirit", "body", "consciousness", "reality" and others with a new emphasis on Being, showing their inadequacy for his new philosophical explorations. Moreover, Heidegger went on to separate his pursuit of "ontology" from the kinds of inquiry that previous researches of "essence" had conducted under the same label, which henceforth, according to Heidegger, should be engaged only in particular fields of science. For Heidegger, the ontical forms of research conducted by scientists presuppose the regional-ontological, which in turn presupposes the fundamental-ontological. As he expresses it:
The question of Being aims… at ascertaining the a priori conditions not only for the possibility of the sciences which examine beings as beings of such and such a type, and, in doing so, already operate with an understanding of Being, but also for the possibility of those ontologies themselves which are prior to the ontical sciences and which provide their foundations. Basically, all ontology, no matter how rich and firmly compacted a system of categories it has at its disposal, remains blind and perverted from its ownmost aim, if it has not first adequately clarified the meaning of Being, and conceived this clarification as its fundamental task.
Earlier philosophers, namely ancient ones, have stated that only in phenomenon was it possible to posit the essence of things. Thus the phenomenon was opposed to essence, and it was the moment of opposition of the subject and object. Husserl had differentiated his new notion of phenomenon from the traditionally accepted notion of phenomenon as "occurrence". The notion of "phenomenon" as introduced by Husserl in his phenomenology carries in itself the two faces of things: phenomenon as "representation of the world as it is reflected in consciousness" and the essence of a thing "as it is in itself". In Husserl's belief, 'phenomenon' as he defined it appeared comprehensive and sufficient for his philosophical ventures. Husserl's perspective, as Heidegger saw it, left some room for new development in phenomenology: bringing "ontology" into "phenomenology" with a new force. For Heidegger, Husserl's ideas were "in exile" with their transcendental tendency, because they were exclusively concerned with consciousness, and they had to be "thrown" back into the historical, external world. From the Heidegger's point of view the attempt of his mentor to design and save life only inside human consciousness, i.e. "the world above" of the transcendental ego, was not sufficient. Thus, the first task that Heidegger took on was to work out how to refute Husserl's immanence of consciousness while preserving all the achievements of his mentor's phenomenology. On the other hand, why did Heidegger want to base his "new phenomenology" only on the category of Being, and to set as his task a formulation and proof of it? Answering this question, he again refers to the phenomenological maxim: without any intention to address directly "things", then what kind of intellectual outlook will be at all possible? To Heidegger the necessary focus is clear: Being in its various forms. Really, I exist, things surrounding me exist, and people surrounding me exist. Here it is important to understand that being is primary; things, I, and people, for instance, are all forms of being. Being reveals itself first of all in its multiplicity, in the form of separate essences. Today there are only two ontological alternatives in philosophy: the "objectivistic" variant of philosophy which was carefully developed by Nicolai Hartmann, and the "subjectivistic" fundamental ontology of Heidegger. For a variety of reasons, recently, the majority of philosophers give preference to the second, to Heidegger's alternative.
Heidegger argues "Dasein is an entity which does not just occur among other entities. Rather it is ontically distinguished by the fact that, in its very Being, that Being is an issue for it". Human beings are in a privileged position to understand fundamental ontology.