Act 3, Sc. 1, lines 112-133: Why is Hamlet's question to Ophelia about where her father is a turning point in their dialogue?

Hamlet. Ha, ha! Are you honest?

Ophelia. My lord?

Hamlet. Are you fair?

Ophelia. What means your lordship?

Hamlet. That if you honest and fair, your honesty should

admit no discourse to your beauty.

Ophelia. Could beauty, my lord, have better commerce than with honesty?

Hamlet. Ay, truly; for the power of beauty will sooner

transform honesty from what it is to a bawd than the force of

honesty can translate beauty into his likeness. This was

sometime a paradox, but now the time gives it proof. I did

love you once.

Ophelia. Indeed, my lord, you made me believe so.

Hamlet. You should not have believed me; for virtue cannot

so inoculate our old stock but we shall relish of it. I loved

you not.

Ophelia. I was the more deceived.

Hamlet. Get thee to a nunnery. Why wouldst thou be a

breeder of sinners? I am myself indifferent honest, but yet I

could accuse me of such things that it were better my mother

had not borne me. I am very proud, revengeful, ambitious,

with more offences at my beck than I have thoughts to put

them in, imagination to give them shape, or time to act them

in. What should such fellows as I do crawling between earth

and heaven? We arrant knaves all; believe none of us. Go

thy ways to a nunnery. Where's your father?