…go still deeper into this matter, that it is not the whiteness, separately regarded, which heightens the intolerable hideousness of that brute; for, analysed, that heightened hideousness, it might be said, only rises from the circumstance, that the irresponsible ferociousness of the creature stands invested in the fleece of celestial innocence and love; and hence, by bringing together two such opposite emotions in our minds, the Polar bear frightens us with so unnatural a contrast.
There are no more uses of "irresponsible" in the book.
Show samples from other sources
After much passing around of money Cousin Joshua was moved across the tracks and placed in state accommodations for the irresponsible, where he remained for the rest of his days.
Harper Lee -- Go Set a Watchman
"The fact of the matter is, we’ve been irresponsible," Marybeth continues.