Full Idea
The details of Mackie's analysis are complex, but the general idea is that the cause is part of a wider set of conditions which suffices for its effect.
Gist of Idea
A cause is part of a wider set of conditions which suffices for its effect
Source
report of J.L. Mackie (Causes and Conditions [1965]) by Tim Crane - Causation 1.3.3
Book Reference
'Philosophy: a Guide Through the Subject', ed/tr. Grayling,A.C. [OUP 1995], p.189
A Reaction
Helpful. Why does something have to be 'the' cause? Immediacy is a vital part of it. A house could be a 'fire waiting to happen'. Oxygen is an INUS condition for a fire.