1. The Stoics teach that all intellectual knowledge takes rise
in sensuous perception. The soul, at first, is like a sheet of
blank paper, on which representations of things are afterwards
delineated by the senses. The beginning of all knowledge is,
therefore, the aisthêsis (perception of sense). This, as soon as
we are conscious of it, becomes a Representation (phantasia) or
mental image. During the formation of this Representation the
Soul is purely passive, the Representation is like the
impression of a seal on wax (tupôsis en psuchê, for which
Chrysippus, to modify the doctrine, substituted heteroiôsis
psuchês, an alteration in the Soul). According to this view, the
object of itself produces its Representation on the subject, and
this Representation manifests itself, and in itself the
corresponding object, to the subject. When we have apprehended
an object, the remembrance of this object remains after the
object has been removed. A large number of memories of this kind
constitute experience (empeiria). 2.