My lord, you know I love you

Iago
My lord, you know I love you.
Othello
I think thou dost;
And for I know thou ‘rt full of love and honesty
And weigh'st thy words before thou giv'st them breath,
Therefore these stops of thine fright me the more.
For such things in a false, disloyal knave
Are tricks of custom; but in a man that's just,
They're close dilations working from the heart
That passion cannot rule.
Iago
For Michael Cassio,
I dare be sworn I think that he is honest.
Othello
I think so too.
Iago
Men should be what they seem;
Or those that be not, would they might seem none!
Othello
Certain, men should be what they seem.
Iago
Why then, I think Cassio's an honest man.
Othello
Nay, yet there's more in this.
I prithee speak to me as to thy thinkings,
As thou dost ruminate, and give thy worst of thoughts
The worst of words.
Iago
Good my lord, pardon me.
Though I am bound to every act of duty,
I am not bound to that all slaves are free to.
Utter my thoughts? Why, say they are vile and false—
As where's that palace whereinto foul things
Sometimes intrude not? Who has that breast so pure
But some uncleanly apprehensions
Keep leets and law days and in sessions sit
With meditations lawful?
Othello
Thou dost conspire against thy friend, Iago,
If thou but think'st him wronged and mak'st his ear
A stranger to thy thoughts.
Iago
I do beseech you,
Though I perchance am vicious in my guess—
As, I confess, it is my nature's plague
To spy into abuses, and oft my jealousy
Shapes faults that are not—that your wisdom
From one that so imperfectly conceits
Would take no notice, nor build yourself a trouble
Out of his scattering and unsure observance.
It were not for your quiet nor your good,
Nor for my manhood, honesty, and wisdom,
To let you know my thoughts.