Full Idea
The unfriendly response to Quine's objection to essentialism is that it conflates the de re and the de dicto. The friendly response is that behind that conflation is a real epistemological problem for essentialism.
Gist of Idea
Quine may have conflated de re and de dicto essentialism, but there is a real epistemological problem
Source
Frank Jackson (Possible Worlds and Necessary A Posteriori [2010], 1)
Book Reference
'Modality', ed/tr. Hale,B/Hoffman,A [OUP 2010], p.257
A Reaction
He cites Richard Cartwright 1968 for the friendly response. The epistemological question is how we can know the essentialness of an essence.