ABSTRACT
The species problem is understood as a result of the contradiction between aspiration and inability to reduce diversity of species conceptions (SCs) to a single one, be it either an overwhelming general or a particular universal. Any SC represents a natural species phenomenon (‘species in general’) in a certain cognitive situation and serves as a heuristic model of this phenomenon. SCs of various levels of generality emerge as a result of sequential multiple reduction cascade; the more reduction steps lead to a particular SC, the less adequate it is for natural species. The entire set of SCs can be represented by a conceptual pyramid, within which various SCs occur as particular interpretations of more general inclusive concepts and have no sense without contexts imposed by them. It is suggested that in order to define natural ‘species in general’, a certain concept of biota should be fixed at the top of the conceptual pyramid, allowing both species and non-species (such as life forms, syntaxa, guilds) phenomena to be defined and distinguished simultaneously. The ontology of the natural species phenomenon is presumably determined by its conjectural essence, i.e., specieshood. The latter is a part of the entire natural history of organisms, so its manifestations are group-specific and evolve with the evolutionary development of the structure of biota.
