Full Idea
The Stoics classified the passions according to the implicit (and erroneous) opinions about the good and bad that they contained.
Gist of Idea
Stoics classify passions according to the opinion of good and bad which they imply
Source
report of Stoic school (fragments/reports [c.200 BCE]) by Charles Taylor - Sources of the Self §8
Book Reference
Taylor,Charles: 'Sources of the Self' [CUP 1992], p.149
A Reaction
This doesn't sound very promising, since nearly all emotions can be put to either a good or a bad use