Full Idea
A totality of conditions necessary for an occurrence is jointly sufficient for it. This is a widely held but controversial view, and it is not a logical truth.
Gist of Idea
A totality of conditions necessary for an occurrence is usually held to be jointly sufficient for it
Source
David H. Sanford (Causation [1995], p.82)
Book Reference
'A Companion to Metaphysics', ed/tr. Kim,Jaegwon/Sosa,Ernest [Blackwell 1995], p.82
A Reaction
This wouldn't work for an impossible occurrence. What are the necessary conditions to produce a large planet made of uranium? One of them would have to be a naturally impossible necessity.