In this talk, I introduce the concept of ontological emergence and present two leading theoretical frameworks that seek to operationalise it. I then assess their respective strengths by examining two paradigmatic cases: functional realisation in artefacts and the emergence of quasiparticles in condensed-matter physics. Finally, I turn to the possible emergence of conscious states from physical states. I outline the specific difficulties raised by this distinctive case and discuss what it reveals about the prospects and limits of ontological emergence.