Short answers, pulled from the story.
Ontology is the philosophical study of being that seeks to determine the fundamental building blocks of the world. It asks what exists and distinguishes between unique particulars and general repeatable universals. This inquiry establishes the core categories of reality from substances to abstract objects.
Aristotle proposed ten categories of being while Plato argued for the objective existence of universals. Thomas Aquinas refined distinctions between existence and essence and René Descartes introduced dualist ontology dividing mind and matter. Later thinkers like Baruch Spinoza argued for monist ontology and Alfred North Whitehead developed process ontology.
Alexius Meinong proposed that nonexistent objects like the Loch Ness Monster are part of being while Bertrand Russell argued only existing things can be subjects of true statements. Modal logic introduces possible worlds and David Lewis claimed these worlds are as real as the actual world. This dispute extends to the nature of possibility and necessity in reality.
Social ontology examines concepts like money and gender which exist as part of the social fabric shaped by human practices. These social kinds lack the objective reality of natural phenomena like elementary particles yet are not pure fictions. Abstract objects such as numbers exist outside space and time and lack causal powers.
The ontological turn in anthropology emerged in the 1990s to focus on how different cultures experience the nature of being. Indigenous communities often ascribe intentionality to non-human entities through a perspective known as animism. This outlook emphasizes the interconnectedness of all living entities and the importance of balance with nature.