The Nature of Lear's Madness; comparing to Edgar

According to the Pocket Oxford Dictionary, 'mad' is defined as 'insane, frenzied; wildly insane'. This is one very constant theme appearing in the drama of King Lear by Shakespeare. There are several characters which raise the question in the audiences' mind, the minds of fellow characters, or in their own minds as to whether they are 'mad'. Some have alternative motivves and methods to the madness they portray; others were truly loosing grasp of stability and reality in their mental state. Two perfect examples and illustrations of this is the situation of 'poor Tom'/Edgar, as compared with King Lear.
King Lear made wild decisions, without putting in any real thought. Being King and the surmountable responsibilities he had, it was 'wildly' insane for him to have given it all up, particularly to persons he knew were unreliable and deceitful. After that fact, he banished the daughter he knew was worthy, honest and respectable. His reason based solely on her inability to express flattery to him... an incompetent reason. He banishes his loyal and close friend and advisor for the same crime of honesty, and with all of these behaviours he continues to become stressed and frightened at the series of events which follow; his daughters underminding him and the discredited names they were bringing upon themselves and the kingdom; their disrespect and disregard for him. He was never calm in his state, but rather, rowdy and commanding- quick to a temper. This was always the case, even when he was wrong. He only continued to make irrational decisions, like staying out in the storm or talking with himself. He did show signs of losing grips of stability and reality. The seriousness of the root of his madness as well as Shakespeare's lack of signals to indicate that it was a deliberate act, all show that King Lear was one of those characters who were sincerely 'mad'.
Poor Tom had a motive and method to his madness. He intended to stay close to his father, find out how the rumours of his treachery came about, and redeem his name if possible. The only way to do this was to obtain a disguise as a character no one would pay attention to. Poor Tom was the perfect candidate, they all let him go where he felt to go and say what he felt to say. He did not do anything wildly insane while as Edgar, therefore it can only be assumed that his wild and insane acts were only in character. When his father comes to him, eyes plucked out, Edgar expresses the want to reveal his true self. Also, in his monologues, Edgar is always speaking something of substance, particularly about what he has learned about the ways of the world and all it's misfortunes. He comments on the characters of Lear and Gloucester as any sane person would, however his madness was assumed because of appearance rather than action.
True madness is not judged by appearance nor is it by labelling, madness is something which goes much more personally and reveals itself in character. Lear was te character which was truly mad, though most characters did not label him as such, it was because he was the king and during his life, he had commanded the respect of so many. Edgar was labelled as mad because of his appearance, his attempt to be mad had a motive which none could consider insane or wild. It was well thought through, and Edgar had all grips on reality.