RODERIGO.
With him! why, 'tis not possible.

IAGO.
Lay thy finger thus, and let thy soul be instructed. Mark me
with what violence she first loved the Moor, but for bragging,
and telling her fantastical lies: and will she love him still for
prating? Let not thy discreet heart think it. Her eye must be
fed; and what delight shall she have to look on the devil? When
the blood is made dull with the act of sport, there should
be,--again to inflame it and to give satiety a fresh appetite,--
loveliness in favour; sympathy in years, manners, and beauties;
all which the Moor is defective in: now, for want of these
required conveniences, her delicate tenderness will find itself
abused, begin to heave the gorge, disrelish and abhor the Moor;
very nature will instruct her in it, and compel her to some
second choice. Now sir, this granted;--as it is a most pregnant
and unforced position,--who stands so eminently in the degree of
this fortune as Cassio does? a knave very voluble; no further
conscionable than in putting on the mere form of civil and
humane seeming, for the better compass of his salt and most
hidden loose affection? why, none; why, none;--a slipper and
subtle knave; a finder out of occasions; that has an eye can
stamp and counterfeit advantages, though true advantage never
present itself: a devilish knave! besides, the knave is
handsome, young, and hath all those requisites in him that folly
and green minds look after: a pestilent complete knave; and the
woman hath found him already.