Full Idea
Stoics say some presentations are sensible, some non-sensible. Those received through the sense organs are sensible; non-sensible are those which come through the intellect, for example, presentations of incorporeals and other things grasped by reason.
Gist of Idea
There are non-sensible presentations, which come to us through the intellect
Source
report of Stoic school (fragments/reports [c.200 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.51
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.13
A Reaction
The a priori used to be metaphysics (a world of truths), and in modern times is epistemology (a mode of justification), but here it is just a mode of experience, which is not, it seems, necessarily true.