 Advocates of the term seek to distinguish 'ontology', which investigates what there is, from 'meta'-ontology, which investigates what we are asking when we ask what there is.Jonathan Schaffer argues that there is a different question for meta-ontology to discuss, namely the classification of ontologies according to the hierarchical connections between the objects in them, and the determination of which objects are fundamental and which are derived.He describes three possible types of ontology