We concede this last point; the classifications under the idea category will likely not hold domain-generally. For these divisions, we propose that the isa relation be under- stood to express conditional subsumption: A isa B, but only in the context of C, ..., Z, B’s ancestors. Let us call this conditional subsumption relationship ‘isa’.29 Rather than supposing that this prevents the InPhO from being a proper ontology, we think the move from isa to isa helps capture precisely the sort of information required for our metadata needs. We believe that this sort of conditional, hierarchically-structured knowledge is important in modeling the ability of philosophical experts to say which topics are most relevant to the examination of particular ideas in particular scholarly contexts. [...] While these observations clarify the issue, it may remain a point of dispute whether a representation based on the isa* relation is properly called an ontology. Our general response to the terminological worries of this section is to acknowledge the need to regiment language for purposes of clarity and precision, but note that all we mean by “ontology” and “dynamic ontology” is precisely what we say in Sect. 2 above. [...] Though we would be reluctant to give up the word “ontology” entirely, readers suffi- ciently bothered by this issue may call the idea section of the InPhO what they like—we place no special importance on its terminological status.