The most ubiquitous model is the dependence model of ontological priority states that "A is prior to B" is true just in case B depends on A for its existence, as in the case where the color of a particular being depends on that being existing for the color-quality inhering in it to exist. The reverse—that A depends on B for its existence—cannot be true. Under this view, a child might be considered as ontologically dependent on its parent, as it needed as parent for its being generated, or a child might not be considered ontologically dependent on its parent, as the child to does not need the parent to maintain itself in existence.
"More Real" Model
A model of ontological priority was developed by Justus Buchler in order to criticize it:
Let uscontrast a principle of ontological priority... with a principle of ontological parity. In terms of the latter, whatever is discriminated in any way... is a natural complex, and no complex is more 'real', more 'natural', more 'genuine', or more 'ultimate' than any other.
This model states for something A to have ontological priority over something B, it is sufficient that A be more real than B. Thus, for a Platonist, the Forms are ontologically prior to sensible beings.
Strawson's Model
develops his own view of ontological priority:
This fact could reasonably be expressed by saying that in our scheme α-particulars were ontologically prior to β-particulars, or were more fundamental or more basic than they.
are entities that make a proposition true. For example, a dog being spotted makes the proposition "The dog is spotted" true. In such a relation, the truth of the proposition depends on the dogs being in a certain way for it to be true.
Substance
are generally understood to be things that do not depend on other things in order to exist. For example, in Aristotle'sCategories, these are individuals, as individuals do not depend on their accidents in order to exist, while accidents do need their individuals in order to exist.
Grounding
Grounding concerns in virtue of what else a proposition holds or some kind of thing is the way it is. This is articulated in the case of the Euthyphro dilemma. In the Euthyphrodialogue, Socrates asks Euthyphro, "Is the pious loved by the gods because it is pious, or is it pious because it is loved by the gods?". Epistemologicalfoundationalists are similarly concerned with what propositions ground other propositions in the order of knowledge.
