It meant that «the light of the Holy Spirit, which is given in a particular way to the pastors of the church,» as Humanae vitae describes it, does not guarantee lack of error or replace human analysis. (religion-online.org)
Complexity depends upon human analysis, which implies intelligibility, while the lack of intelligibility allows no conclusion whatever. (faith.org.uk)
The problem is that we are told that Jesus was the Son of God by the human authors of Scripture but with proper human analyses the passages that indicate there is a link have been found to be embellishments. (religion.blogs.cnn.com)