Full Idea
We hold fast to the position, defended by Chrysippus, that every proposition is either true or false.
Gist of Idea
Every proposition is either true or false
Source
report of Chrysippus (fragments/reports [c.240 BCE]) by M. Tullius Cicero - On Fate ('De fato') 38
Book Reference
'The Hellenistic Philosophers:Vol.1 translations', ed/tr. Long,A. /Sedley,D. [CUP 1987], p.203
A Reaction
I am intrigued to know exactly how you defend this claim. It may depend what you mean by a proposition. A badly expressed proposition may have indeterminate truth, quite apart from the vague, the undecidable etc.