In this scene, Rochester is trying to convince Jane to live with him without the benefit of matrimony. He tries appealing to her feelings for him, essentially telling her that he'll go to the devil without her in his life. Also, he says that, since she is an orphan with no family to be affected by the scandal, she will be hurting no one by living in sin with him. Jane is heartbroken because she truly loves him but she steadfastly refuses to compromise her principles, correctly pointing out that they wouldn't be worth much if she abandoned them when they became inconvenient to her. Since this is exactly what Rochester has done, he doesn't take her refusal well.
"Do as I do: trust in God and yourself. Believe in heaven. Hope to meet again there."
"Then you will not yield?"
"Then you condemn me to live wretched and to die accursed?" His voice rose.
"I advise you to live sinless, and I wish you to die tranquil."
"Then you snatch love and innocence from me? You fling me back on lust for a passion — vice for an occupation?"
"Mr. Rochester, I no more assign this fate to you than I grasp at it for myself. We were born to strive and endure — you as well as I: do so. You will forget me before I forget you."
"You make me a liar by such language: you sully my honour. I declared I could not change: you tell me to my face I shall change soon. And what a distortion in your judgment, what a perversity in your ideas, is proved by your conduct! Is it better to drive a fellow-creature to despair than to transgress a mere human law, no man being injured by the breach? for you have neither relatives nor acquaintances whom you need fear to offend by living with me?"
This was true: and while he spoke my very conscience and reason turned traitors against me, and charged me with crime in resisting him. They spoke almost as loud as Feeling: and that clamoured wildly. "Oh, comply!" it said. "Think of his misery; think of his danger — look at his state when left alone; remember his headlong nature; consider the recklessness following on despair — soothe him; save him; love him; tell him you love him and will be his. Who in the world cares for you? or who will be injured by what you do?"
Still indomitable was the reply — "I care for myself. The more solitary, the more friendless, the more unsustained I am, the more I will respect myself. I will keep the law given by God; sanctioned by man. I will hold to the principles received by me when I was sane, and not mad — as I am now. Laws and principles are not for the times when there is no temptation: they are for such moments as this, when body and soul rise in mutiny against their rigour; stringent are they; inviolate they shall be. If at my individual convenience I might break them, what would be their worth? They have a worth — so I have always believed; and if I cannot believe it now, it is because I am insane — quite insane: with my veins running fire, and my heart beating faster than I can count its throbs. Preconceived opinions, foregone determinations, are all I have at this hour to stand by: there I plant my foot."