It was clear to him that the experimental method was the only method by which one could arrive at any scientific analysis of the passions; and certainly Dorian Gray was a subject made to his hand, and seemed to promise rich and fruitful results. His sudden mad love for Sibyl Vane was a psychological phenomenon of no small interest. There was no doubt that curiosity had much to do with it, curiosity and the desire for new experiences; yet it was not a simple but rather a very complex passion. What there was in it of the purely sensuous instinct of boyhood had been transformed by the workings of the imagination, changed into something that seemed to the boy himself to be remote from sense, and was for that very reason all the more dangerous. It was the passions about whose origin we deceived ourselves that tyrannized most strongly over us. Our weakest motives were those of whose nature we were conscious. It often happened that when we thought we were experimenting on others we were really experimenting on ourselves.
While Lord Henry sat dreaming on these things, a knock came to the door, and his valet entered, and reminded him it was time to dress  for dinner. He got up and looked out into the street. The sunset had smitten into scarlet gold the upper windows of the houses opposite. The panes glowed like plates of heated metal. The sky above was like a faded rose. He thought of Dorian Gray’s young fiery-colored life, and wondered how it was all going to end.
When he arrived home, about half-past twelve o’clock, he saw a telegram lying on the hall-table. He opened it and found it was from Dorian. It was to tell him that he was engaged to be married to Sibyl Vane.
[...32] “I suppose you have heard the news, Basil?” said Lord Henry on the following evening, as Hallward was shown into a little private room at the Bristol where dinner had been laid for three.
“No, Harry,” answered Hallward, giving his hat and coat to the bowing waiter. “What is it? Nothing about politics, I hope? They don’t interest me. There is hardly a single person in the House of Commons worth painting; though many of them would be the better for a little whitewashing.”
“Dorian Gray is engaged to be married,” said Lord Henry, watching him as he spoke.
Hallward turned perfectly pale, and a curious look flashed for a moment into his eyes, and then passed away, leaving them dull. “Dorian engaged to be married!” he cried. “Impossible!”
“It is perfectly true.”
“To some little actress or other.”
“I can’t believe it. Dorian is far too sensible.”
“Dorian is far too wise not to do foolish things now and then, my dear Basil.”
“Marriage is hardly a thing that one can do now and then, Harry,” said Hallward, smiling.
“Except in America. But I didn’t say he was married. I said he was engaged to be married. There is a great difference. I have a distinct remembrance of being married, but I have no recollection at all of being engaged. I am inclined to think that I never was engaged.”