T H E D O C T R I N E OF I N T E L L E C T 29 proceeds ‘scientific’ knowledge. The emphasis on certainty and con­ viction is of course of Stoic origin; for the Stoics certainty was a kind of knowledge: ἄλλην δ ὲ (ἐπιστήμην) ἕξιν ϕαντασι ω v(ε ὑπò λόγου ήντινά ϕασιν ἐv τόνῳ καἰ δυνάμει (τ η ς ψνχ η ς) κε ι σθαι (Stobaeus, Eel., I I , 128). Nevertheless, Avicenna’s theory has obviously a very different orientation from the Stoic one, for here certainty is creative of knowledge and not something attached to it in the mind as a criterion of its truth, although the fact, that the Stoics could call this mere mental atti tude knowledge, is significant. I t seems that this Stoic doctrine of certainty in relation to knowledge played a progressively increasing part in the early Christian centuries as Stoicism came to be blended more and more with Platonism (and neo-Pythagoreanism). In one direction it led to the Ciceronian-Stoic doctrine of the immediate certainty of all knowledge based on the notion of the inchoatae or adumbratae intelligentae.