History
The word comes from the Ancient Greek μή, me "non" and ὄν, on "being" (confer ontology). It refers not exactly to the study of what does not exist, but an attempt to cover what may remain outside of ontology. Meontology has a slim tradition in the West (see Sophist and negative theology), but has always been central to the Eastern philosophies of Taoism and the later Buddhism.
Nishida was the first to thoroughly expand the Eastern notion of nothingness in the Continental paradigm and is thus responsible for bringing to the West a clearer understanding of the Buddhist notion of non-being.
It can also be associated more recently, with the emphasis placed upon absence or deferral by both Martin Heidegger and Jacques Derrida.
French philosopher Jean-Luc Nancy distinguishes nothingness from nothing. He writes, “Nothingness is not nothing [rien]....There is no ontology without the dialectic or the paradox of a meontology....Nothing is the thing tending toward its pure and simple being of a thing.” Hence Being itself is nothingness. Nothing is “the vanishing, momentary quality of the smallest amount of beingness (étantité).”
Levinas on meontology
For Emmanuel Levinas, what was meontological was what had meaning beyond being, beyond ontology; for him this was the ethical, the primary demand of the other in the face-to-face encounter. In this sense he sought to clarify or take further some of the issues raised by Heidegger and explicitly give ontology a secondary role to ethics rather than continue to parallel them in saying that the Being means care (German: Sorge).