Indeed, when the hear-ers are rude and ignorant, nothing more is necessary in the speaker than to inflame their passions.
Once again, there's the assumption that it's a function of the content of the crowd, rather than a function of crowds themselves, that is assumed to be at work.
But the multitude, the vu/gm, are overpowered and car-ried along by their appetite, which is tumultuous and turbulent; their soul is tainted, having con-tmcted a contagion from the body,
Thinking of this scene from Men In Black, where J explains to K that "a person is smart, people are dumb, panicky animals." J's more egalitarian, it's something about crowd size rather than an inherent problem in the body of the common multitude, but it's built on the same observation that you can't speak to the masses the same way you might talk to a peer. J endorses secrecy for their own good, Vico endorses explaining it in a simplified way, then raising the discourse over time.