Yes; just as if you were speaking Greek. I feel I have adequate cause to be happy, and I _will_ be happy. Goodbye!
Chapter 34 · Jane Eyre
Context
Jane responds to St. John's long speech urging her toward higher ambitions by saying she cannot understand his reasoning and insists on her right to happiness before saying goodbye.
Analysis
The simile 'as if you were speaking Greek' dismisses St. John's moral vocabulary as a foreign language Jane refuses to learn—not because she lacks intelligence, but because she rejects the premises. Her repeated 'I will be happy' uses future tense as defiance, a speech act that claims the right to self-determination. The abrupt 'Goodbye!' cuts off further persuasion, ending the conversation on her terms.
Essay Tip
Support a thesis that Jane's power in the novel often lies in refusal and exit—this quote shows her simply declining to engage with value systems that negate her needs.