Sixtus of Siena opens the fifth book of the Bibliotheca Sancta by explaining why a book of censures on the holy Fathers is an act of piety rather than of impudence. Two kinds of men, he says, do harm: heretics who dig out the Fathers’ rare slips to dress their own errors in borrowed authority — and rigorists who, finding one flaw, condemn a whole holy work. Against both he sets a figure from Genesis:

…following in this the footsteps of their most wicked author, Ham: who not only did not cover the nakedness of his father Noah, but proclaimed it to the rest to be mocked. But contrariwise the other brothers, Shem and Japheth, far unlike their brother, endured neither to look themselves upon the father’s nakedness which was to be revered, nor to have it looked upon by others, but, turned away (as it is written), covered it — showing by such an example that the errors of the holy Fathers, if not to be approved, are yet rather to be concealed than to be published.

The whole book that follows — 264 annotations of exactly such errors — is Sixtus walking that line: correcting without mocking, covering without approving.

Read it in full: the Preface of the Fifth Book.