Noun
(philosophy) Essence; quiddity.
Quality; quantity.
Source: en.wiktionary.orgEvery questioning is a seeking. Every seeking takes its direction beforehand from what is sought. Questioning is a knowing search for beings in their thatness and whatness. Martin Heidegger
This led medieval logicians to distinguish between what they called the quid nominis or "whatness of the name", and the underlying nature common to all the things it names, which they called the quid rei or "whatness of the thing". Source: Internet
Even the focus of traditional ontology on the 'whatness' or 'quidditas' of beings in their substantial, standing presence can be shifted to pose the question of the 'whoness' of human being itself. Source: Internet