In Paradise Lost, why is Adam's high praise of Eve from lines 546-59 in Book Eight inappropriate?
There is something particularly ironic about the words Adam uses in praise of Eve, as he has just talked about her many deficiencies. Clearly, the way that he is overwhelmed with love for her brushes aside the many problems that Adam sees in the character of Eve. If we just quickly examine the lines prior to the section you have indicated, we can see the many problematic issues that Adam sees in Eve's character:
...at least on her bestow'd
Too much of Ornament, in outward shew
Elaborate, of inward less exact.
For well I understand in the prime end
Of Nature her th' inferiour, in the mind
And inward Faculties, which most excell,
In outward also her resembling less
His Image who made both, and less expressing
The character of that Dominion giv'n
O're other Creatures...
Even then is less intellectually able than Adam, is based more on outward show than inner substance, and finally possesses less of the divine image that Adam so clearly displays. These are rather massive deficiencies which of course are overlooked by Adam because of Eve's physical allure.