General principle, one applied to the largest numbers (6)
I believe the answer is:
Here is my best explanation:
'the largest numbers' is the definition.
(I've seen this before)
'general principle one applied to' is the wordplay.
'general principle' becomes 'maxim' (I've seen this before).
'one' becomes 'a'.
'applied to' is a charade indicator (letters next to each other).
(Other definitions for maxima that I've seen before include "Largest amounts", "peaks", "upper limits)", "Greatest amounts", "High points", "greatest possible amounts", "The greatest amounts", "extremely high values", "Largest numbers" and "Highest points".)