This plainly is the source of the quote. And … it is not a quote at all. It is a summary, by Peter Tompkins, of what he believes that Innocent was saying, in some unspecified text. Whether it is a fair summary or not I could not say; there is, as we can see, no footnote on the paragraph. Whether the supposed verbatim quotations are in fact accurate we cannot tell, but I have my doubts about these also.