The best models for lunar origin are the testable ones.

A few related questions:

1. Who came up with it? If it was, in fact, someone named Taylor (which it need not be), which Taylor?
2. Is there a paper/talk/etc that contains a definitive form of Taylor's axiom?
3. I think we can all agree that testable models are the best ones. Why, then, did Taylor's axiom even need to be stated? e.g. was there a time when when untestable theories of lunar formation were in vogue or something?

This statement may have triggered some discussion on the issue of testability, because a prefatory page in the conference record that I found described in Robert Malcuit, Geoforming Mars: How could nature have made Mars more like Earth?, Springer 2021, p. 142, supposedly reads as follows:

The Page Before the PREFACE (Unlabeled Page VI) Has a Few Interesting Comments by at Least Two of the Participants (in Approximately the Same Format as the Page in the Book)

TAYLORS'S AXIOM
The best models for lunar origin are the testable ones.

TAYLOR's COROLLARY
The testable models for lunar origin are wrong. — S. Ross Taylor paraphrased by Sean Solomon, at the Conference on the Origin of the Moon, Kona, 1984.

So far I have been unable to find a scan of the relevant page of the conference proceedings online to confirm this description, however I found a blog post "The Genesis of the Moon" that provides matching information. Google provides merely snippet views (1, 2, 3) of page VI, just enough to confirm that this page holds the relevant information.