Michael Patton from ReclaimingTheMind elaborates here on whether the early church fathers believed in the doctrine of Sola Scriptura (I address this cardinal doctrine here on its relationship to apostasy.)
Sometimes people get the idea that sola Scriptura was a 16th-century invention. While it was definitely articulated a great deal through the controversies during the Reformation, its basic principles can be found deep in church history.
... The clearest token of the prestige enjoyed by (Scripture) is the fact that almost the entire theological effort of the Fathers, whether their aims were polemical or constructive, was expended upon what amounted to the exposition of the Bible. Further, it was everywhere taken for granted that, for any doctrine to win acceptance, it had first to establish its Scriptural basis (Early Christian Doctrines, San Francisco: Harper & Row, 1978, pp. 42, 46).