Full Idea
If something is offered as a candidate necessary a posteriori truth, how could we show that it is necessary, in the face of the fact that it takes investigation to show that it is true, and so, in some sense, it might have turned out to be false?
Gist of Idea
How can you show the necessity of an a posteriori necessity, if it might turn out to be false?
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
This is the topic of his paper, which he compares with how we can know that essences are essential.