According to the following passage from "Rappaccini's Daughter," how can Rappaccinis love for his daughter as a father be explained?...

Rappacini's
name is connotative of the adjective rapacious which means excessively
grasping or greedy. Using his daughter, who looks "redundant with life, health, and
energy" Rappacini, a ruthless scientist, has given her superhuman powers as she has grown
up surrounded by bizarre flowers of both poisonous and exotic qualities from which she draws
unnatural powers such as immunity from the deadly effects of these plants.

In
essence, Rappacini's daughter has become a part of her father's garden herself. For, she has
developed a sisterly relationship with one particular plant that bears a "profusion of
purple blossoms" that possess the luster of precious gems. Beatrice embraces this plant
that her father is cautious around, never touching it.

"Yes, my sister, my splendor, it shall be Beatrices's task to nurse and to serve
thee; and thou shalt reward her with thy kisses and perfumed breath, which to her is as the
breath of life."

But, when Giovanni, who is smitten
with her, enters the garden, she must deny him the promise of one of the "gems" from
the exotic purple plant, warning him that to touch the plant if fatal. Thus, because it does not
harm her, Beatrice has become an anomaly and a victim of her father's insane zeal for science.
For, because of her unnatural powers, she is alienated from the rest of the world.

However, because Giovanni has breathed her poisonous breath so much, he now can be with
her without harm. Unfortunately, he is not aware of this; instead, he convinces Beatrice that
she can take a potion that Professor Baglioni has given him and she will no longer be poisonous.
He tells her, "Shall we not quaff it together, and thus be purified from
evil?"

When Rapaccini spots his daughter in the garden with Giovanni, he
comes forward to tell her that he has devised a method for her to be with Giovanni. But, as he
spreads his hands over the two of them, Giovanni trembles and Beatrice shudders; for, they are
the hands that have "thrown poison into the stream of their lives."  Beatrice feebly
asks her father why he has inflicted a miserable doom upon her. 

At this
point, in the passage cited above, Rapaccini, asks her why she claims to be miserable. Why is it
misery to have the powers he has endowed her with, he asks. He cannot understand why Beatrice
would rather be a weak woman like all others when she can be so puissant that she can strike
down any enemy. He has made her invulnerable in order to preserve her life, he tells his
daughter.

But, Beatrice asks him, Oh, was there not, from the first, more
poison in thy nature than in mine? because he has selfishly kept her for himself. She has not
been able to love a man without harming him. Truly, Rappacini's love has been selfish as he has
kept Beatrice for his own in his deadly perfection of her; he has valued his scientific powers
over consideration for Beatrice's feelings and her need to be like others.