Passivity

Un ministre est excusable du mal qu’il fait, lorsque le gouvernail de l’État est forcé dans sa main par les tempêtes; mais dans le calme il est coupable de tout le bien qu’il ne fait pas. (A minister of state is excusable for the harm he does when the helm of government has forced his hand in a storm; but in the calm he is guilty of all the good he does not do.)

Commonly paraphrased:  Every man is guilty of all the good he did not do.