First paragraph (not abstract): Ontology is often described as the inquiry into what exists, but there is some disagreement among (meta-) ontologists about what “existence” means and whether there are different kinds or senses of “existence” or just one; that is, whether “existence” is equivocal or univocal. Furthermore, there is a growing number of philosophers (many of whom take inspiration from Aristotle’s metaphysical writings) who argue that ontology should not be concerned so much with what exists, but with what is fundamental or real (or something similar). Each of the positions in this debate is centered on a concept or small class of concepts that is intended to capture what ontology is about. Examples of such ontological core conc...