From the article:
"Rhetoric was a primary subject in formal learning from antiquity to the middle of the 19th century, when it was replaced by the study of literature and absorbed into the kind of English department we all recognize today. Exactly why it fell out of favor is a matter of debate, but now that rhetoric has made an academic comeback in the past 50 years as a distinct discipline, we would do well to know what it is and why it is so important."
“[I]t is absurd to hold that a man ought to be ashamed of being unable to defend himself with his limbs, but not of being unable to defend himself with speech and reason.” (Aristotle)
"This is to say that language is inadequate for conveying one’s thoughts and discoveries to others clearly and directly. No two people can understand something exactly the same way. Thus, even if absolute truth exists, human language is inadequate for conveying it precisely. "
The complete article: Why Rhetoric Still Matters