Sola Scritura, or Scriture Alone, is a dangerous doctrine. The Scritures need a common interpretation. Without that, we have the thousands of Protestant denominations, each interpreting the Scripture on their own. The doctine of our Faith can be thought of as a Trinity. Scripture is the word of God revealed to us, the Fathers are the correct interpretation of the Scritpures, and the Lives of the Saints are the Scriptures in motion. In fact, I have often heard the Lives of the Saints called "The Continuation of the Acts of the Apostles", just as we could consider the writings of the Fathers as a "Continuation of the Holy Epistle". This rich collection of Truth, the majority of it outside of Scripture, but interpreting Scripture, is what separates us from the Protestants, and for that matter, the Latin Church. In the one, they have a Pope to interpret the Scripture. In the other, each man is his own Pope.