Context:
Johnson's tall and robust figure combined with his odd gestures were confusing to some; when William Hogarth first saw Johnson standing near a window in Samuel Richardson's house, "shaking his head and rolling himself about in a strange ridiculous manner", Hogarth thought Johnson an "
ideot, whom his relations had put under the care of Mr. Richardson".[195] Hogarth was quite surprised when "this figure stalked forwards to where he and Mr. Richardson were sitting and all at once took up the argument ... [with] such a power of eloquence, that Hogarth looked at him with astonishment, and actually imagined that this
ideot had been at the moment inspired".[195] Beyond appearance, Adam Smith claimed that "Johnson knew more books than any man alive",[196] while Edmund Burke thought that if Johnson were to join Parliament, he "certainly would have been the greatest speaker that ever was there".[197] Johnson relied on a unique form of rhetoric, and he is well known for his "refutation" of Bishop Berkeley's immaterialism, his claim that matter did not actually exist but only seemed to exist:[198] during a conversation with Boswell, Johnson powerfully stomped a nearby stone and proclaimed of Berkeley's theory, "I refute it thus!"[194]
More:
https://en.wikipedia.org/wiki/Samuel_Johnson#Character_sketch