Despite, or perhaps because, rhetoric has fallen broadly into disrepute through abuse by twentieth century nationalisms and, more significantly because more generally, through a mechanized and scientistic anthropology, its value and its virtue for persuasion in politics, in ecclesiastical affairs, and in other areas need to be recovered.
Here’s why.
Rhetoric seen in the whole conspectus of its function is an art of emphasis embodying an order of desire. Rhetoric is advisory; it has the office of advising men with reference to an independent order of goods and with reference to their particular situation as it relates to these. The honest rhetorician therefore has two things in mind: a vision of how matters should go ideally and ethically and a consideration of the special circumstances of his auditors. (Richard Weaver, from the lecture “Language is Sermonic,” p. 211 in the collection Language is Sermonic)
Rhetoric address the whole man–reason and emotions, mind and heart–and treats man as man, as whole human being. Man will be persuaded one way or another, and it is better if he is persuaded to something good and noble.
We are all of us preachers in private or public capacities. We have no sooner uttered words than we have given impulse to other people to look at the world, or some small part of it, in our way. Thus caught up in a great web of inter-communication and inter-influence, we speak as rhetoricians affecting one another for good or ill. That is why I must agree with Quintilian that the true orator is the good man, skilled in speaking–good in his formed character and right in his ethical philosophy. (ibid., p. 224)