Definition of Soliloquy
If Edgar can reveal his thoughts and plans through soliloquy, it is only fair that his bastard brother, Edmund, would get the chance to do the same. In Act 1, Scene 2, Edmund finally gets the opportunity to air his grievances directly to the audience.
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,”
When my dimensions are as well compact,
My mind as generous and my shape as true
As honest madam’s issue? Why brand they us
With “base,” with “baseness,” “bastardy,” “base,"
[...]
Edmund the base
Shall top th' legitimate. I grow, I prosper.
Now, gods, stand up for bastards!
As characters change their clothes, their manners of speech, and even their entire identities, Shakespeare uses the soliloquy as a crucial device to clue the audience in on the inner machinations guiding even the most outwardly insane behavior. In Act 2, Scene 4, after Gloucester disinherits Edgar and casts him out from his hold, Edgar undertakes a startling transformation and reveals his thought process to the audience:
Unlock with LitCharts A+Whiles I may ’scape,
I will preserve myself, and am bethought
To take the basest and most poorest shape
That ever penury in contempt of man
Brought near to beast. My face I’ll grime with filth,
Blanket my loins, elf all my hair in knots,
And with presented nakedness outface
The winds and persecutions of the sky.
The country gives me proof and precedent
Of Bedlam beggars, who with roaring voices
Strike in their numbed and mortified bare arms Pins, wooden pricks, nails, sprigs of rosemary,
[…]
“Poor Turlygod!” “Poor Tom!"
That’s something yet. Edgar I nothing am.