Madame Pernelle: "Children, I take my leave much vexed in spirit. I offer good advice but you won't hear it. You all break in and chatter on and on. It's like a madhouse with the keeper gone." (1.1.5)
Madame Pernelle considers Orgon's family to be mad; as we find out, however, they "break in and chatter on and on" in attempt to persuade Madame Pernelle that her ideas are, in fact, crazy.
Madame Pernelle: "These visits, balls, and parties in which you revel Are nothing but inventions of the Devil. […] People are driven half-insane At such affairs, where noise and folly reign And reputations perish thick and fast. As a wise preacher said on Sunday last, Parties are Towers of Babylon, because The guests all babble on with never a pause;" (1.1.34)
Madame Pernelle's description of "visits, balls, and parties" is similar to the chaos that Tartuffe has brought to Orgon's house.
Cléante: "My, what a scene she made, and what a din! And how this man Tartuffe has taken her in!"
Dorine: "Her son is worse deceived; His folly must be seen to be believed." (1.2.3-4)
Dorine's claim is a bit hard to swallow, but seeing is believing in this case; Orgon really is worse deceived.
Dorine: "Your wife, two days ago, had a bad fever, And a fierce headache which refused to leave her.
Orgon: "Ah. And Tartuffe?"
Dorine: "Tartuffe? Why he's round and red, Bursting with health and excellently fed."
Orgon: "Poor fellow!" (1.4.4-6)
Orgon's reaction is totally illogical to the point of being disturbing. It's as if he can't hear what Dorine is saying.
Cléante: "That girl was laughing in your face, and though I've no wish to offend you, even so I'm bound to say that she had some excuse. How can you possibly be such a goose? Are you so dazed by this man's hocus-pocus That all the world, save him, is out of focus?" (1.5.1)
Cléante talks of Tartuffe as if he is a magician and of Orgon as if he is his unwitting target.
Dorine: "All right, then: we believe you, sad to say. But how a man like you, who looks so wise And wears a mustache of such splendid size, Can be so foolish as to…" (2.2.14)
Dorine makes fun of Orgon by mocking the notion of "looking wise." Orgon may look like a distinguished older man, but he's still remarkably foolish.
Dorine: "I tell you, lovers are completely mad!" (2.4.85)
Dorine's observation is right in line with the French expression l'amour fou, or crazy love. The lovers' little spat can be thought of as a brief moment of madness.
Dorine (To Mariane): "Your father's addled; he's acting like a dunce. Therefore you'd better humor the old fossil. Pretend to yield to him, be sweet and docile, And then postpone, as often as necessary, The day on which you have agreed to marry." (2.4.90)
Rather than try to reason with a fool (Orgon), Dorine decides it would be best to simply string him along until some more drastic measure can be taken.
Orgon: "Enough, by God! I'm through with pious men: Henceforth I'll hate the whole false brotherhood, And persecute them worse than Satan could."
Cléante: "Ah, there you go – extravagant as ever! Why can you not be rational? You never Manage to take the middle course, it seems, But jump, instead, between absurd extremes." (5.1.10-11)
Orgon's actions prove that, just because you can cure a fool of one illusion, without curing him of being a fool.
Orgon: "You're talking nonsense. Can't you realize I saw it; saw it; saw it with my eyes? Saw, do you understand me? Must I shout it Into your ears before you'll cease to doubt it?" (5.3.17)
Here, Orgon gets a taste of his own medicine; he gets to see what it's like to argue with a fool.