Ontology is the branch of metaphysics which deals with the study of being, existence and reality. It concerns the categories of being of both the physical (objects) and the abstract (categories, properties, etc.) and attempts to create clear conceptions of the metaphysical relationships.
Categories of Being
The categories of being are categories which are extended to objects of inquiry. These categories usually include: physical object, mind, classes, properties, relations, space and time, propositions, and events. The relations between these categories are disputed by metaphysicians.
Descartes considered extension the primary property of physical objects. According to this definition, a physical object, then, must necessarily exist in two dimensions, and must have mass. Historically, it has been maintained (notably by Spinoza) that subjects belonging to one category of being can only act on other subjects in the same category. So, physical objects can only act, and be acted on by, other physical objects.
The status of other categories is in dispute. While it is rare for philosophers to dispute the existence of physical objects, it is common to dispute the status and cause of categories and the mental representation of physical objects in the form of propositions.
Ontological status pertains to the existence of a subject under particular circumstances, and is distinguished by John Searle as being a matter of subjectivity and objectivity. An object has a subjective ontology if it exists only in the presence of a mind representing the subject. An object has an objective ontology if its existence is not dependent on the presence of a mind representing the subject. For Searle, subjective ontology is, first and foremost, a property of minds themselves (as the major property of a mind is its ability to represent itself).
- Example: A rock falls into a pond. The event has objective ontology.
- Example: Al and Bob make an agreement that they will not steal from each other. The agreement has a subjective ontology.
The matter of distinction is over whether or not the subject (the rock or the reflection) would 'exist' in the event that the mind was absent. In the case of the rock, the explanation is simple enough. The rock falls into the pond regardless of whether or not there is a mind there to represent it. In the case of the agreement, the agreement only exists as long as the minds of Al and Bob are representing the agreement. Searle refers to the agreement as a social fact, in contrast to the rock falling into the pond, which is a fact per the Tractatus. Searle's view of ontological status is formative in his view of consciousness, as he asserts that objects with subjective ontology are not reducible to constituent parts, and consciousness is one of those objects that has a subjective ontology.
Application to Theology and Apologetics
While it is not that common for discussions of ontology to leave philosophical conversation, the concept can be easily applied to discussions of the existence of God. Discussions of ontological status are important, as they address whether or not God, in the given model, is supposed to be a physical object. If it is the case that God is a physical object, then God has the property of extension, and this is valuable for discussing falsifiability in the context of existence/non-existence.
In contrast, there are a number of important social theorists, like Marx and Durkheim who characterize God as a social fact, but not as a physical object. Because God is a social fact, this shifts the ontological status in a way that collapses a lot of theistic claims. For example, if God is a social fact, then all of the causal power of the idea is realized only through other agents; God cannot do anything, as an cause or material cause, but can only be a mental cause for individuals acting in the world. This makes God more identifiable with the concept of law than with some creator or law-giver.
Objective Ontology and God
Most conventional definitions of God require that God have some sort of objective ontological status. In order to perform many of the functions that are attributed to such a God (i.e. Creating the Universe, communicating law, etc.) an objective ontology is required. Because God has an objective ontology, it is generally accepted that any claims about God are synthetic a posteriori claims.
Synthetic a posteriori claims are subject to verification and, in order to be epistemologically valid, must be falsifiable.