4 adjectives to describe heedlessness

I mean the cynicism of the dwellers in that place; I mean their insensibility, their indifference and calm heedlessness in the presence of such grave subjects for thought.

And the English, with their characteristic heedlessness, have never troubled to disillusion him.

Mercy, while deploring the occasional levity of the queen's conduct, and her immoderate thirst for amusement, had constantly looked forward to the birth of a child as the event which, by the fresh and engrossing occupation it would afford to her mind, would be the surest remedy for her juvenile heedlessness.

And so, today, though conscious of no fault, I stand before you sullied, and atone For youthful heedlessness that passed for wrong.

4 adjectives to describe  heedlessness