Disguise, I see thou art a wickedness,
Wherein the pregnant enemy does much (II.ii.)

Here, Viola first becomes aware of Olivia’s newfound affection for Cesario and laments the unintended consequences of her disguise. In this scene, Viola decides that the use of deception is a convenient vehicle for evil influences. She also suggests that women in general are more susceptible to deceptions. This quote is significant as it marks the first time a character openly rebukes disguise and deception as a malevolent force, capable of misleading and causing inadvertent damage.

Well, I’ll put it on and I will dissemble myself in’t;
and I would I were the first that ever dissembled in such a gown (IV.ii.)

Here, Feste is asked by Sir Toby to dress up as a priest in order to fool Malvolio, now imprisoned as a madman. Feste’s disguise as priest is integral to a mock-exorcism that Sir Toby wishes to orchestrate. Once again, Feste makes a rather incisive observation, pointing to other priests who don the gowns of the office but are only pretending or “dissembling” to play the part. Shakespeare uses this pun to satirize the church, wherein unscrupulous and deceptive priests can uphold their authority by merely wearing the proper garments.

…Cesario, come,
For so you shall be, while you are a man,
But when in other habits you are seen,
Orsino’s mistress, and his fancy’s queen. (V.i.)

By this point, Viola has revealed her true identity and Duke Orsino has agreed to marry her. He claims that once Viola has shed her disguise, she will be the queen of his love. However, this line is significant because Orsino insists on addressing Viola as her male alias even though he no longer has to. Some scholars point to this line as evidence that Orsino is enamored more by the disguise than by Viola herself.