Definition of haecceity in US English:



  • 1That property or quality of a thing by virtue of which it is unique or describable as “this (one).”.

    • ‘But it has extra-mental existence only in the particular things in which it exists, and in them it is always ‘contracted’ by the haecceity.’
    • ‘Smooth space is filled by events or haecceities, far more than by formed and perceived things.’
    • ‘Understanding concepts in his philosophy (eg., faciality, virtuality, haecceity, types of becoming, and rhizome) is important as they provide to entry points into some of the issues under examination.’
    • ‘For historical reasons, such a property is called a haecceity -- literally, a ‘thisness.’’
    • ‘Although it might seem to be a highly fanciful notion, it is hardly more fanciful than some haecceity theories which employ the same distinction, nor perhaps than some possible worlds theories either.’
    1. 1.1 The property of being a unique and individual thing.
      • ‘It is the entire assemblage in its individuated aggregate that is a haecceity; it is this assemblage that is defined by a longitude and a latitude, by speeds and affects, independently of forms and subjects, which belong to another plane.’
      • ‘Not that it actually matters, but that is the haecceity of the question and its answer.’
      • ‘There's the haecceity, the isness, the standing reserve, that's one thing: the world.’
      • ‘The haecceity of a thing is what makes this particular thing what it is in particular.’


Mid 17th century: from medieval Latin haecceitas, from Latin haec, feminine of hic ‘this’.