Where does the doctrine of S-of-S come from? Primarily from 2 Timothy 2:15 to 18 and secondarily from Deuteronomy 29:29 and Revelation 22:18-19. Grudem outlines the doctrine formally in his Systematic Theology. However it is also a central feature of evangelical belief about the Bible. For example the Anglican '39 Articles' says "Holy Scripture contains all things necessary to salvation." The Westminster Confession says "The whole counsel of God concerning all things necessary for His own glory, man's salvation, faith and life." The modern 'Gospel Coalition,' an interdenominational grouping of evangelicals say in their doctrinal statement; "[special revelation is] sufficient for all that God requires us to believe and do." From a modern perspective the author of this article; 'Is the Bible Hermeneutically self-sufficient?' argues that given that Scripture is self-attesting about itself, it naturally follows that Scripture is self-sufficient for it's own interpretation. For real complexity and depth go to Word and Supplement: Speech Acts, Biblical Texts and the Sufficiency of Scripture by Timothy Ward, who argues that philosophically, 'biblical texts' are independent, in a sense, from both the authors and readers. The purpose of the author is carried out by the text and the reader creates interpretations but once the text comes into existence neither can altar it.