Thou, nature, art my goddess; to thy law
My services are bound. Wherefore should I
Stand in the plague of custom, and permit
The curiosity of nations to deprive me,
For that I am some twelve or fourteen moonshines
Lag of a brother? Why bastard? wherefore base?

Legitimate Edgar, I must have your land.
Our father’s love is to the bastard Edmund
As to the legitimate. Fine word—“legitimate”!
Well, my legitimate, if this letter speed,
And my invention thrive, Edmund the base
Shall top the legitimate. I grow; I prosper.
Now, gods, stand up for bastards!

Edmund delivers this soliloquy just before he tricks his father, Gloucester, into believing that Gloucester’s legitimate son, Edgar, is plotting against him (1.2.1–22). “I grow; I prosper,” he says, and these words define his character throughout the play. Deprived by his bastard birth of the respect and rank that he believes to be rightfully his, Edmund sets about raising himself by his own efforts, forging personal prosperity through treachery and betrayals. The repeated use of the epithet “legitimate” in reference to Edgar reveals Edmund’s obsession with his brother’s enviable status as their father’s rightful heir. With its attack on the “plague of custom,” this quotation embodies Edmund’s resentment of the social order of the world and his accompanying craving for respect and power. He invokes “nature” because only in the unregulated, anarchic scheme of the natural world can one of such low birth achieve his goals. He wants recognition more than anything else—perhaps, it is suggested later, because of the familial love that has been denied him—and he sets about getting that recognition by any means necessary.