Answer :
The key idea that O'Connell and Thomas Merton agreed on was nonviolence.
Why O'Connell believed in Nonviolence
O'Connell believed that violence was not the way to solve issues. This was what became his philosophy after he killed a man in a duel.
His philosophy was what inspired freedom fighters like Gandhi and Martin Luther King.
Why Thomas believed in nonviolence
According to Thomas Merton, a society can never be transformed through violence.
From his word, violence only brings about hatred which would also lead to more violence.
Read more on Thomas Merton here:
https://brainly.com/question/4726196