Artificial inventions rely much more overtly on an audience's opinions and beliefs. Like inartificial inventions, they also seek to establish truth, but they do so by presenting opinion rather than hard fact. Specifically, much inartificial invention is thought to be a topical invention. Commonplaces are general or reiterated propositions. Drugs are bad.
Blondes have more fun.
Looking someone in the eye means you're telling the truth. This does not necessarily mean that plain style sounds uneducated, but instead that it wraps its smarts in the talk of the home town crowd. This means that middle style sounds educated and that it puts its ideas into the voice of the six o'clock news. This does not necessarily mean that grand style sounds educated, but instead that it chooses its words, places its ideas, and conveys its message with the beliefs of its listeners firmly in sight .