Not but what he could feel with mettlesome youth which, caring nought for the mows of dotards or the gruntlings of the severe, is ever (as the chaste fancy of the Holy Writer expresses it) for eating of the tree forbid it yet not so far forth as to pretermit humanity upon any condition soever towards a gentlewoman when she was about her lawful occasions.
There are no more uses of "mettle" in the book.
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The Trials are a test of my mettle.
Sabaa Tahir -- An Ember in the Ashes
But I will say, too, that for every man who showed no fear or hesitance, there were three or four or five others whose mettle was as unashamedly wan and mortal as yours or mine.