Perhaps one of the most notable quotes to do with this important theme in this great tragedy is Iago's confession of how and why he chooses to follow "the Moor" Othello, whilst loathing him at the same time in Act I scene 1. Note the way that reference is explicitly made to the two contrasting states of appearance and reality:
Were I the Moor I would not be Iago.
In following him I follow but myself;
Heaven is my judge, not I for love and duty,
But seeming so for my peculiar end.
For when my outward action doth demonstrate
The native act and figure of my heart
In compliment extern, ’tis not long after
But I will wear my heart upon my sleeve
For daws to peck at. I am not what I am. (I.i.57–65)
Note the way in which Iago confesses his plan of attack to Roderigo. His "loyalty" to his master does not emerge from any sense of goodness or "duty," but is based on Iago's belief that he is able to trick and manipulate Othello so that he can gain revenge. Those who are in reality what they appear to be are foolish, because to do this makes you incredibly vulnerable, and leaves your heart exposed, "For daws to peck at." His final mysterious comment, "I am not what I am," could summarise the character of Iago, who seems to be engaged in a constant game of deception, both to others who he apparently takes into his confidence, such as Roderigo, but also the audience themselves, as we struggle to work out who the "real" Iago really is. Appearance and reality are thus shown to be in conflict through this early speech of Iago.