Full Idea
There can be no effect but from a sufficient and necessary cause.
Gist of Idea
An effect needs a sufficient and necessary cause
Source
Thomas Hobbes (De Corpore (Elements, First Section) [1655], 2.10.02)
Book Reference
Hobbes,Thomas: 'Metaphysical Writings', ed/tr. Calkins,Mary Whiton [Open Court 1905], p.77
A Reaction
To be compared with Mackie's subtler modern account of this matter. If two different separate causes could lead to the same result, it is hard to see how the cause must be 'necessary' (unless you say they lead to different effects).
Related Idea
Idea 8333 A cause is an Insufficient but Necessary part of an Unnecessary but Sufficient condition [Mackie]