"Ethical negative-utilitarianism is a value-system which challenges the moral symmetry of pleasure and pain. It doesn't question the value of enhancing the happiness of the already happy. Yet it attaches value in a distinctively moral sense of the term only to actions which tend to minimise or eliminate suffering. This is what matters above all else."
January 1, 1970
https://en.wikiquote.org/wiki/Negative_utilitarianism