Final answer:
Aristotle believed that humans are at the apex of the 'Great Chain of Being', due to the unique capacity of the human soul for reason, which differentiates humans from plants and animals.
Step-by-step explanation:
According to Aristotle, humans are the apex of the "Great Chain of Being." Aristotle's perspective is that all living beings have souls, but the capacities of these souls differ significantly across species. Plants possess a vegetative soul responsible for growth and nutrient exchange. Animals have a soul that adds the capacities for desire and voluntary movement. However, it is uniquely the human soul that possesses the capacity for rational thought and reasoning, placing humans at the pinnacle of the natural world in Aristotle's hierarchical structure.