In obsolete|lang=en terms the difference between properness and property
is that
properness is (obsolete) excellence, quality while
property is (obsolete) to make a property of; to appropriate.
As nouns the difference between properness and property
is that
properness is (obsolete) excellence, quality while
property is something that is owned.
As a verb property is
(obsolete) to invest with properties, or qualities.