Full Idea
The evil which occurs in terrible disasters has a rationale [logos] peculiar to itself: for in a sense it occurs in accordance with universal reason, and is not without usefulness in relation to the whole. For without it there could be no good.
Gist of Idea
There is a rationale in terrible disasters; they are useful to the whole, and make good possible
Source
Chrysippus (fragments/reports [c.240 BCE]), quoted by A.A. Long - Hellenistic Philosophy 4.4.5
Book Reference
Long,A.A.: 'Hellenistic Philosophy' [Duckworth 1986], p.169
A Reaction
[a quotation from Chrysippus. Plutarch, Comm Not 1065b] A nice question about any terrible disaster is whether it is in some way 'useful', if we take a broader view of things. Almost everything has a good aspect, from that perspective.