Power is the ability to manipulate and control whatever one desires; to do what one pleases to do without answering to authority. The power that corrupts the characters plays an extensive role throughout Shakespeare's play, King Lear. Goneril and Regan are corrupted by the power that Lear offers them. Edmund's corruption comes from the trust of his father. Absolute power corrupts absolutely with the characters, because once have full control, they are so cold that they will do anything to keep the power - or to gain more. The quest for power corrupts, but when absolute power is attained, treachery and deceit is the only path to take.
The power that Lear gives to Goneril and Regan makes them treacherous and deceitful. Lear offers his land to his daughters - Goneril and Regan - but in return they must profess their love for him: "which of you shall we say doth love us most, that we our largest bounty may extend." (1, 1, 56-57) By doing this, Lear gives an opportunity for his daughters to take advantage of him. Goneril "loves [him] more than words can wield the matter' (1, 1, 60) and the same goes for Regan saying, "[Goneril] comes too short, that [she] profess [herself] an enemy of all other joys." (1, 1, 79-80) They don't really love Lear, but instead they love the power that Lear gives them. Once Lear had given the land to his daughters, the power that they have corrupts them. When Lear needs a place to stay, the daughters are not quick to react; Goneril allows him to stay but he must "disquanty his train" (1, 4, 126).
She even goes to the extent of making Oswald "slack of former services" (1, 3, 10) to Lear in an attempt to make him leave. Regan is no better, when Lear comes to her door looking for a place to stay, "the old man and's people cannot me well bestowed." (2, 4, 330-331) That if Lear wants to stay then he has to give up his followers. The power corrupts them into treacherous beings, where respect and honor for their father are less important than their own well-being. The power that makes Edmund corrupt is trust. He uses the trust to manipulate and control his father for the benefit of himself. He frames his brother by composing a false letter to his father implicating a plot to kill Gloucester, that when "our father would sleep till I waked him, you should enjoy half his revenue forever." (1, 2, 55-56) Gloucester replies with "this villain of mine comes under the prediction of mine: there's son against father" (1, 2, 112-117) This shows that Gloucester had great faith and trust in his son Edgar.
To better his plan he goes to Edgar and convinces him to run away. The thought that he would frame his own brother for the chance to gain power shows his corruption, and that he will do anything to have more power. Edmund writes another letter, except this implicates his father in a plot with France to kill The Duke of Cornwall. He does this so that "the younger rises [and] the old doth fall" (3, 4, 25) and he will become the Earl. Edmund is so corrupted and blinded by his quest for power that he is willing to jeopardize his father's life for a chance at being the Earl.
Absolute power corrupts absolutely with the characters Regan, Goneril, and Edmund. This power blinds them into seeing nothing except the quest for total control. Regan and Goneril gain absolute power over their father's land that they banish Lear - their own father - from their castle, and leaves him outside in the storm. Edmund's quest for power doesn't stop at any pace, he goes to the extent of letting Cornwall "pluck out [Gloucester] poor old eyes" (3, 7, 70) for trying to kill him. Edmund's absolute power corrupts him into a deceitful, deceptive person to gain as much control over his family as possible. Absolute power corrupts them absolutely; they try their hardest to take control over their family, that in the end they pay consequences in full.
When power it obtained it corrupts, when absolute power is achieved then there is no other way to go besides perversion. Lear gives Goneril and Regan their power and craves for more, and will go to any means to get it. Edmund craves power and goes to any means to get it; by plotting against his father and brother. Absolute power corrupts these characters because their quest for power leaves them with treachery and deceit. When given in moderation power is controlled; when given in excess, power becomes a corrupter..