It has been the result of thoughtlessness, rather than of malignity.
However, he now experienced sudden remorse for his thoughtlessness.
Fine would then interpose, with a thoughtlessness of which she soon repented.
Earnestness is the path of immortality (Nirvana), thoughtlessness the path of death.
People praise earnestness; thoughtlessness is always blamed.
Shocked at his own thoughtlessness, he sprang to his feet and walked hastily to the terrace.
She blamed herself for her thoughtlessness, and resolved that it should not be so in future.
You and the rest were all guilty of a piece of gross thoughtlessness.
That's the trouble with thoughtlessness; it never remembers other people.
Thoughtlessness, carelessness, procrastination—and then it was too late.