François Bordes on how to tell the difference between a Mousterian point and a convergent scraper:

The best way to decide is to haft the piece and try to kill a bear with it. If the result is successful, then it is a point; if not, then it should be considered a convergent scraper. One of the problems with this approach is that it can quickly exhaust the available supply of bears or typologists

– As paraphrased by André Debénath and Harold L. Dibble in Handbook of Paleolithic Typology: Lower and Middle Paleolithic of Europe (1994)

Debénath & Dibble on the sheer scale of what lies beneath:

Imagine … that during the time of the Acheulian in Europe, which lasted for at least 500,000 years, there was a constant population of 5,000 active tool makers. Imagine also that each of these flintknappers made only ten bifaces per year and perhaps 100 flake tools. Even with such conservative parameters…, this would have resulted in the production of 25,000,000,000 bifaces and 250,000,000,000 flake tools, of which only a minuscule proportion has been collected during the history of Paleolithic research.

– André Debénath and Harold L. Dibble in Handbook of Paleolithic Typology: Lower and Middle Paleolithic of Europe (1994)