Samuel Johnson's dictionary 3rd edition 1766 defines rhetoric as:
The act of speaking not merely with propriety, but with art and elegance.
The power of persuasion; oratory
The spelling has changed since Johnson’s time and the meaning has shifted somewhat too, acquiring a distinctly pejorative tone. For example – the argument is mere rhetoric, not worth switching my ears on.
Johnson understood perfectly well that argument is about winning and rhetoric is by far the most useful tool you have. He was determined to win any argument, once admitting he’d argue against his own beliefs simply for the intellectual pleasure of winning.
Now that science has a tenuous, but rapidly loosening grip on our notions of truth, we have come to regard rhetoric as a slick, question-begging device, only fit for politicians and other charlatans. Yet rhetoric is easy to slip into isn’t it? It’s easy to take sides in an argument with the hope of winning, or at least coming out on top. Easy to cite untrustworthy organisations, dodgy scientists, partial data and cherry-picked statistics, easy to use them as rhetorical devices. Merely to win, to be on the winning side, the side with the most powerful, the most fashionable, most rewarding rhetoric.
A good word to inform our susceptibilities I’d say.