Abstract I am a realist and argue that biological species exist in nature. I also argue that the validity of findings of the many disciplines within the natural sciences employing biological species in their endeavours of inquiry are unequivocally linked to the accuracy of the species used in experiments. Few scientists today see the fundamental importance of taxonomic and systematic studies in both addressing accuracy of diversity and the delineation of species diversity for other areas of science. The basic controversial issues in the debate revolve around opinions regarding the nature of species as either Individuals or Classes, confusion of Species as a taxonomic category and as entities in nature, the varied practitioners studying diversity, a general lack of a Lineage perspective and a gross chauvinistic perspective on the types of data worthy of exposing and delineating diversity. I argue that species in nature are Individuals and form Lineages. As Individuals, they cannot be defined but can only be diagnosed in time. The category Species is a Class with a definition. The difficulties realised by scientists studying biodiversity in ‘defining’ a species hinges upon the fact that as natural entities they cannot be defined. Recognizing and understanding the origins of characters in species is further complicated if one views species in nature as Classes and lacks an appreciation for the Lineage and the origin and retention of traits through time. This forms an interesting paradox that many scientists have fallen victim to wherein species are viewed as Classes (hence definable, but immutable) yet are used to understand the process of descent that involves lineages and Individuals! The pre‐Darwinian Class perspective of species, combined with a common chauvinistic perspective on characters ultimately delays progress and places a ‘glass ceiling’ on species diversity for planet Earth. One resolution to the species and species concept issue is to view the concepts in a hierarchical manner of primary (theoretical) and secondary (operational) concepts. Interestingly, the issue of Individuals versus Classes for naturally occurring entities is much more widespread and exists in many other scientific fields. Thus, a hierarchical perspective of having a primary, nonoperational concept for natural entities and multiple operational concepts serving as ‘tools’ for discovering natural things consistent with the primary concept is a heuristic methodology that is applicable to the advancement of many areas of science.
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