There are times when a stern word is necessary, when a child needs a firm reminder, when social justice demands harsh measures.
Of their own, these acts are unwholesome—only their context redeems them.
Think of them as toxic medicines, to be administered with great care. Once they are no longer necessary or can be replaced with more wholesome means, they are no longer medicine, but poison.
Likkutei Sichot, vol. 15, p. 39