He defines the soul as Entelechy, which means that all things develop according to natural design, and because of this, they do not just happen. However, human beings are complex creatures, and they can fail in their journey to achieve their ultimate goal, which is to follow their own Entelechy to become themselves. His vision saw three types of souls. The lowest level is the nutritive soul, which survives by absorbing matter from something else. Then there is a second, which is the sensitive soul, which is the level of sensations and perceptions. Finally, there is the rational soul, which understands the first two, and which is further capable of analyzing and making decisions. The third and final level is also the highest, that capable of intelligence and responsible for the functioning of the human being. When I asked an Italian relative what she believed the soul to be, she replied that it is that spiritual part of ourselves that draws us closer to God and guides us in distinguishing good and good.