The appeal to Scripture alone was in part an appeal to origins, in part – and inseparably – an appeal directly to Christ. ‘If we abide in the old doctrine which the apostles taught, and hearken to no new learning’, says Tyndale, ‘then abide we in the Son (for upon the Son build they us), and in the Father through confidence in the Son; and are heirs of everlasting life.’ Calvin explains that Christ says that Scripture itself is his witness: ‘Search the Scriptures … they are they which testify of me’ (John 5.39).‘Without [the Gospel] we should be ignorant of the great blessings and promises which Jesus Christ has given us … This is what we should in short seek in the whole of Scripture: truly to know Jesus Christ, and the infinite riches that are comprised in him.’ William Whitaker lists three ‘witnesses to himself’ used by Christ: ‘First, the works which he performed; secondly his Father who sent him; thirdly the holy Scriptures themselves, which he calls his witnesses.‘

There is, however, a logical difficulty here. Can Scripture authorise its own authority? William Whitaker quotes Thomas Stapleton's answer to this problem: ‘Scripture (says he) cannot be proved by Scripture: therefore it must be proved by the Church; and consequently the authority of the Church is greater than that of Scripture.’ Whitaker's answer is one which goes back to Origen at least: that the Bible is not attesting itself; there is another witness between the Bible and its readers, authenticating the first to the second. The Holy Spirit is this witness; it is he who ‘makes the Scripture canonical and authentic in itself’,