Virtue? A fig!

Only Sir Olivier has the stones (and the talent) to play Othello in blackface. Do not try this at home, kids.

Every deceitful villain in literature, film, and pop culture has Iago's DNA in their blood. From Professor Moriarty to Loki, Dennis Nedry to Gollum, anyone who presents themselves as trustworthy while they smile and smile and work to betray our heroes has descended from that granddaddy of evil genius who could drive a man to murder with nought but a wave of a handkerchief. 

With 1097 lines,* Iago is third only to Richard III (1152) and Hamlet (1422) in pure lung power (per play... Hal/Henry V, whose breath sweeps through three plays, has over 1800 lines, and Falstaff has over 1600 in his three appearances). What does he accomplish with all this vocal ability, other than a whole lot of soap operatic trouble?

As with all Shakespearean villains, he speaks hard truths that cannot be cast aside with all his lies. The speech I chose strikes me as one of those particularly obvious observations of human nature. He is honest after all, since Iago is well aware that he is a perfect example of one who has chosen to sow his own seeds of villainy. He is the quintessential example of how WRONG Polonius** is when he utters   

"To thine own self be true, And it must follow, as the night the day, Thou canst not then be false to any man." Iago is true to himself, and yet is false to everyone. 

After all his silver-tongued philosophizing, one line haunts me the most. It's Iago's final line in the play, directed at Othello after Iago's one-man complot has been exposed: 

"Demand me nothing; what you know, you know:

From this time forth I never will speak word."

Lodovico's immediate response is "What, not to pray?" and Gratiano grumbles "Torments will ope your lips." But Othello stares at Iago and says "Well, thou dost best."

Iago's felt slighted the entire time, ever since Othello made Cassio his lieutenant, and perhaps even before that, as this line suggests. They appear to have a secret between them, and despite Iago's attempt to ruin Othello's good name, when Iago's honesty is finally stained, the bastard decides to zip his lip. What  have they seen and done together in their battles and voyages? What makes Iago loathe and love Othello so much? Why do I love Iago more than Polonius? Because in the end, Iago is honest.

Othello, Act I, Sc. III

Iago: Virtue! a fig! 'tis in ourselves that we are thus

or thus. Our bodies are our gardens, to the which
our wills are gardeners: so that if we will plant
nettles, or sow lettuce, set hyssop and weed up
thyme, supply it with one gender of herbs, or
distract it with many, either to have it sterile
with idleness, or manured with industry, why, the
power and corrigible authority of this lies in our
wills. If the balance of our lives had not one
scale of reason to poise another of sensuality, the
blood and baseness of our natures would conduct us
to most preposterous conclusions: but we have
reason to cool our raging motions, our carnal
stings, our unbitted lusts, whereof I take this that
you call love to be a sect or scion.

*The actual numbers of lines depend on the version/edition you read, but you get the idea.
**I fucking HATE this quote because everyone uses it out of context and they never seem to realize that everyone in Shakespeare's time understood it to be an empty, banal platitude worthy of so much eye-rolling.