From thing +‎ -ness.

thingness (usually uncountable, plural thingnesses)

1. (philosophy) The quality of a material thing; objectivity; actuality; reality.
   • 1994, Shadia B Drury, Alexandre Kojève [1]

     To live as a thing, to live for another and as the other expects, is to live unauthentically or in bad faith. To be true to oneself, one must reduce others to thingness and resist being so reduced.

   • 1998, William C Chittick, The Self-Disclosure of God‎^[2]:

     Whether we dwell in the thingness of fixity or the thingness of wujūd, we are “at” the wujūd of the Real.

   • 2002, Kai Hammermeister, The German Aesthetic Tradition‎^[3]:

     The thingness of a thing precedes the conscious perception of its sensual properties.

• thinghood

• "thingness", Merriam-Webster's Collegiate Dictionary, <http://www.m-w.com/dictionary/thingness> [Retrieved January 8, 2005].
• "thingness", Encarta World English Dictionary, <http://encarta.msn.com/encnet/features/dictionary/DictionaryResults.aspx?refid=1861719723> [Retrieved January 8, 2005].
• "thingness", Random House Unabridged Dictionary (1997) <http://www.infoplease.com/dictionary/thingness> [Retrieved January 8, 2005].

• se'nnights, sennights