Full Idea
The Stoics say when a human being is born, the leading part of his soul is like a sheet of paper ready for being written on. On this he inscribes every one of his conceptions. The first manner of writing on it is through the senses.
Gist of Idea
Stoics say we are born like a blank sheet of paper; the first concepts on it are sensations
Source
report of Stoic school (fragments/reports [c.200 BCE]) by Pseudo-Plutarch - On the Doctrine of the Philosophers 900a
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.48
A Reaction
This may not be dogmatic empiricism, because later inscriptions on the sheet could be purely a priori.