I think that part of the narrative description of these events is to reflect the larger collision between the desire of the soul and the tugging of the flesh. Deledda articulates a world in The Mother where individuals are "are trapped people, from whom one burden is lifted only for another to fall." Part of this burden is seen in how the world of the flesh is always in competition with the aspirations of the soul.
Maria's initial seduction is offset by her belief that she must strive to keep herself pure. In pursuing her own chaste and notion of purity that is devoid of physical pleasure, Maria articulates a vision of reality where she is poised between the world of the flesh and the heavenly desire of the soul. When Maria follows Paul and falls asleep, the vision of "the devil" in the form of old priest tells her that human beings' purpose is to pursue earthly enjoyment. Combined with her insistence that Paul remain pure are representations of how Maria embodies the collision between both worlds. The description of her seduction in a non- judgmental manner helps to evoke how the individual is trapped between two worlds. Navigating this collision forms the basic definition of human identity.
Paul's identity is positioned in a similar manner. His frequenting the prostitute is a reflection of a world constructed for him where the recognition of the divine takes priority. While Maria moved from the world of the flesh to the world of the divine, Paul starts off in the realm of the divine and moves back into the flesh. He finds himself fascinated with the world of the flesh, and struggles to recognize his notion of self as divine as opposed to his own sense of being as a man. He vacillates between both domains of being. His frequenting of the prostitute and its description in a non- judgmental manner is a reflection of such a consciousness. Similar to his affair with Agnes, Paul finds himself embodying "the passionate complex of a primitive populace."
The lack of judgment in articulating the world of the flesh preserves the basic collision that individuals experience in Deledda's thematic world. These are individuals that already feel the weight of the earth upon them. There is no need to judge them further. They do this for themselves. The ending in which the earth's reality smashes both mother and sun through Agnes's eyes helps to evoke this. Deledda does not need to judge the characters. Their behavior is normalized in a larger context in which the struggle for the divine and to shed the earthly desires is part of being in the world. Through refraining from judgment, Deledda is able to illuminate the larger struggle that Paul and his mother embody in the narrative.