Othello is unruffled by Brabantio’s slanderous claims regarding his marriage with Desdemona. He was presumably expecting some sort of backlash, and seems well-prepared to defend himself of the charges of bewitching Desdemona.
My services, which I have done the signiory
Shall out-tongue his complaints.
Despite Iago’s attempts to incite him to dramatic reaction, Othello’s earliest reactions show that he believes his service to the state already has him favored by the Senate –
I fetch my life and being
From men of royal siege; and my demerits
May speak unbonneted to as proud a fortune
As this that I have reach'd.
Othello is also calm as he knows that his relationship with Desdemona is honorable and respectful, so his conscience is clear of any wrongdoing-
My parts, my title, and my perfect soul
Shall manifest me rightly.
Othello is not intimidated when Brabantio and his men draw their swords-
Keep up your bright swords, for the dew will rust
Good signior, you shall more command with years
Than with your weapons
He says that Brabantio’s age rather than his weapon will gain him respect. As a seasoned fighter, Othello would be unperturbed at such an aggressive gesture. He agrees that they should approach the Duke to discuss the matter further.