Goneril and Regan do not hate their father, King Lear. This is what is a little eerie about their relationship with him and what makes them seem so inhuman. They care nothing about him at all. He is a non-person. It is very easy for them to lie about how much they love him, since they have no true emotions to hide. It is a little uncanny how they can express their love in such glowing terms without feeling a thing. Edmund is very much like Goneril and Regan with regard to his father, the Earl of Gloucester. Edmund does not hate the old man at all. He cares nothing about him. For him, Goneril, and Regan, Lear is only in the way, and his kingdom and property are things they expect and feel they deserve to acquire. This idea is expressed in the forged letter which Gloucester takes from Edmund and reads aloud:
This policy and reverence of age makes the world bitter to the best of our times; keeps our fortunes from us till our oldness cannot relish them. I begin to find an idle and fond bondage in the oppression of aged tyranny; who sways, not as it hath power, but as it is suffered. Come to me, that of this I may speak more. If our father would sleep till I waked him, you should enjoy half his revenue for ever, and live the beloved of your brother, EDGAR (Act I, Scene 2).
This same cynical notion is expressed by the Duke masquerading as a friar in Act III, Scene 1 of Measure for Measure, where he is supposedly consoling the condemned Claudio:
Friend hast thou none; For thine own bowels, which do call thee sire, The mere effusion of thy proper loins, Do curse the gout, serpigo, and the rheum, For ending thee no sooner.