ontological

/ˌɑntəˈlɑʤɪkəl/

Other forms: ontologically

Things that have to do with the nature of being are ontological, like your ontological question about the Loch Ness Monster — do we have to have proof in order for something to exist?

The study of being, is called ontology, so an ontological argument might investigate whether God — or people, for that matter — really exist. Are we real or just an imagined phenomenon? How do we know we aren't just characters in our creator's mind? These are heavy questions — philosophers including Aristotle, Parmenides, Descartes, Hume, Kant have all weighed in on the ontological question of “what can we be certain exists?”

Definitions of ontological

1. adjective

   of or relating to ontology
   “ontological speculations”