Pronunciation: [ðˈɪsnəs] (IPA) 
The word "thisness" is a philosophical term that refers to the unique quality or essence of an individual thing or experience. It is spelled with the letter "t" followed by the digraph "h" and then the vowel sound "ɪ" (as in "pit"), followed by the consonant sounds "s" and "n" and the vowel sound "ə" (as in "about"). The IPA phonetic transcription of "thisness" is /ˈðɪsnəs/, with stress on the second syllable.
Thisness is a philosophical term that refers to the particular characteristics or qualities that distinguish something, allowing it to be recognized as a unique entity. It is the individuality or essence of a specific object, event, or experience that sets it apart from others.
The concept of thisness emphasizes the idea that each thing in the world possesses its own distinct identity, separate from anything else. It captures the intrinsic nature and specific properties that make something what it is at a given moment. Thisness is often associated with the idea of personal identity, highlighting the traits or features that make a person recognizable as themselves.
According to the philosopher Duns Scotus, thisness is the ultimate reality that cannot be reduced to general categories or abstract ideas. It represents the concrete existence of a particular thing, encapsulating its unique characteristics or qualities that cannot be fully captured by concepts or language alone.
In essence, thisness recognizes the singularity and individuality of each thing in the world, emphasizing the importance of appreciating and understanding the distinctive features that define its existence. It allows us to recognize and perceive the world in all its richness and diversity, acknowledging that every object or experience possesses its own inherent thisness, which contributes to the intricate tapestry of the universe.
The term thisness was coined by the philosopher and theologian Duns Scotus (c. 1266-1308), also known as John Duns Scotus, as a translation of the Latin term haecceitas. Haecceitas comes from the Latin words haec meaning this and ceitas meaning ness or nessness.
