What two aspects of life are noted at the beginning of this chapter?

There are actually two different examples we could use for your question. First, we have the aspect of life and death..... Fagin's hold over Oliver, and the way he controls the boy. Second, we have friendship and ingratitude, subtly mixed and woven with forethought. Fagin's words, without doubt, inspired the desired effect of guilt and fear in the little boy.

Mr. Fagin took the opportunity of reading Oliver a long lecture on the crying sin of ingratitude; of which he clearly demonstrated he had been guilty, to no ordinary extent, in wilfully absenting himself from the society of his anxious friends; and, still more, in endeavouring to escape from them after so much trouble and expense had been incurred in his recovery. Mr. Fagin laid great stress on the fact of his having taken Oliver in, and cherished him, when, without his timely aid, he might have perished with hunger; and he related the dismal and affecting history of a young lad whom, in his philanthropy, he had succoured under parallel circumstances, but who, proving unworthy of his confidence and evincing a desire to communicate with the police, had unfortunately come to be hanged at the Old Bailey one morning.

Mr. Fagin concluded by drawing a rather disagreeable picture of the discomforts of hanging; and, with great friendliness and politeness of manner, expressed his anxious hopes that he might never be obliged to submit Oliver Twist to that unpleasant operation.