Quote 1
ANTONIO
We all were sea-swallowed, though some cast again,
And by that destiny to perform an act
Whereof what's past is prologue, what to come
In yours and my discharge. (2.1.287-290)
Being sea-swallowed and removed from the court gives the traitors the freedom to do what would otherwise be an unthinkable act. The island has no rules.
Quote 2
ANTONIO
Let's all sink wi' th' king.
SEBASTIAN
Let's take leave of him. (1.1.66-67)
From the first sign that things might not be rosy, Sebastian shows he has no loyalty to his brother or his king (Alonso is both). He has a partner in callousness in Antonio—this foreshadows their later treachery on the island.
Quote 3
ANTONIO
Nor I. My spirits are nimble.
They fell together all, as by consent.
They dropped as by a thunderstroke. What might,
Worthy Sebastian? O, what might—? No more.
And yet me thinks I see it in thy face
What thou shouldst be. Th' occasion speaks thee, and
My strong imagination sees a crown
Dropping upon thy head.
SEBASTIAN
What, art thou waking?
ANTONIO
Do you not hear me speak?
SEBASTIAN
I do, and surely
It is a sleepy language and thou speak'st
Out of thy sleep. (2.1.224-236)
The betrayal Antonio suggests is so heinous as to be unfathomable to Sebastian at first. It seems that once you gain something by betrayal, you're willing to do it over and over again, because it works so well… until it doesn't. (Think of Macbeth's gains and downfall here.)
Quote 4
SEBASTIAN
I remember
You did supplant your brother Prospero.
ANTONIO
True,
And look how well my garments sit upon me,
Much feater than before. My brother's servants
Were then my fellows; now they are my men.
SEBASTIAN
But, for your conscience?
ANTONIO
Ay, sir, where lies that? (2.1.310-317)
Antonio comes easily to his acts of betrayal because he has no conscience, or at the least he represses it well. (Actually, we think he doesn't have one.) Antonio is an example of how one's conscience can get worn out; evil acts become easier and easier with practice.
Quote 5
SEBASTIAN
Sir, you may thank yourself for this great loss,
That would not bless our Europe with your daughter,
But rather lose her to an African,
Where she at least is banished from your eye,
Who hath cause to wet the grief on 't. (2.1.131-135)
Sebastian has no pity, really. It's no wonder he could move so easily from mercilessness to treachery.
Quote 6
ADRIAN
The air breathes upon us here most sweetly.
SEBASTIAN
As if it had lungs and rotten ones.
ANTONIO
Or as 'twere perfumed by a fen.
GONZALO
Here is everything advantageous to life.
ANTONIO
True, save means to live.
SEBASTIAN
Of that there's none, or little.
GONZALO
How lush and lusty the grass looks! How
green!
ANTONIO
The ground indeed is tawny.
SEBASTIAN
With an eye of green in 't.
ANTONIO
He misses not much.
SEBASTIAN
No, he doth but mistake the truth totally. (2.1.49-60)
Reality reflects the nature of the speaker. This is not because reality is false, but because perspective is paramount.
Quote 7
SEBASTIAN
A living drollery! Now I will believe
That there are unicorns, that in Arabia
There is one tree, the phoenix' throne, one phoenix
At this hour reigning there.
ANTONIO
I'll believe both;
And what does else want credit, come to me
And I'll be sworn 'tis true. Travellers ne'er did lie,
Though fools at home condemn 'em.
GONZALO
If in Naples
I should report this now, would they believe me?
If I should say, I saw such islanders—
For, certes, these are people of the island—
Who, though they are of monstrous shape, yet note
Their manners are more gentle, kind, than of
Our human generation you shall find
Many, nay, almost any. (3.3.26-41)
Once one fantasy is proven true, the seer can no longer trust what he believes to be reality.