This excerpt describes the tortured delight that Giovanni feels about Beatrice. Like a youthful suitor, he in infatuated with her and can think of nothing else. On the other hand, his memory of her poisoning innocent insects, plants, and animals horrifies him.
For many days after this incident, the young man avoided the window that looked into Doctor Rappaccini's garden, as if something ugly and monstrous would have blasted his eye-sight, had he been betrayed into a glance. He felt conscious of having put himself, to a certain extent, within the influence of an unintelligible power, by the communication which he had opened with Beatrice. The wisest course would have been, if his heart were in any real danger, to quit his lodgings and Padua itself, at once; the next wiser, to have accustomed himself, as far as possible, to the familiar and day-light view of Beatrice; thus bringing her rigidly and systematically within the limits of ordinary experience. Least of all, while avoiding her sight, should Giovanni have remained so near this extraordinary being, that the proximity and possibility even of intercourse, should give a kind of substance and reality to the wild vagaries which his imagination ran riot continually in producing. Guasconti had not a deep heart--or at all events, its depths were not sounded now--but he had a quick fancy, and an ardent southern temperament, which rose every instant to a higher fever-pitch. Whether or no Beatrice possessed those terrible attributes--that fatal breath--the affinity with those so beautiful and deadly flowers--which were indicated by what Giovanni had witnessed, she had at least instilled a fierce and subtle poison into his system. It was not love, although her rich beauty was a madness to him; nor horror, even while he fancied her spirit to be imbued with the same baneful essence that seemed to pervade her physical frame; but a wild offspring of both love and horror that had each parent in it, and burned like one and shivered like the other. Giovanni knew not what to dread; still less did he know what to hope; yet hope and dread kept a continual warfare in his breast, alternately vanquishing one another and starting up afresh to renew the contest. Blessed are all simple emotions, be they dark or bright! It is the lurid intermixture of the two that produces the illuminating blaze of the infernal regions.