Full Idea
Moderate Haecceitism says that thisnesses and transworld identities are primitive, but logically connected with suchnesses. ..Extreme Haecceitism involves the rejection of all logical connections between suchness and thisness, for persons.
Clarification
'Thisness' is basic identity; 'Suchness' is essence
Gist of Idea
Haecceitism may or may not involve some logical connection to essence
Source
report of Robert Merrihew Adams (Primitive Thisness and Primitive Identity [1979]) by Penelope Mackie - How Things Might Have Been
Book Reference
Mackie,Penelope: 'How Things Might Have Been' [OUP 2006], p.152
A Reaction
I am coming to the conclusion that they are not linked. That thisness is a feature of our conceptual thinking, and is utterly atomistic and content-free, while suchness is rich and a feature of reality.