Of course, the number of entries in a dictionary is more important than whether it has a torn cover, at least if you ever plan on using it for anything. But if you’re only presented with a single dictionary, and it has 20,000 entries, the number 20,000 doesn’t mean very much. Is it a little? A lot? Who knows? It’s non-evaluable. The torn cover, on the other hand—that stands out. That has a definite affective valence: namely, bad.
