The relationship between Platonism and Christianity, which has been widely and controversially discussed in research, is examined in this work through the lens of the human soul, a common subject in both Platonic and early Christian thought. Gregory of Nyssa, a significant theologian of the early Church, addressed this topic in several writings. The Platonic tradition provided him with extensive material for his treatises, particularly on this issue. The work analyzes the theoretical foundations of Gregory's Platonic borrowings. To this end, Gregory's person and life are explored, and the use of Platonic material by him is discussed against the backdrop of the working methods of the time and his own views on the significance of non-Christian thought. Subsequently, the work compares Gregory's views with those of Plato, Plotinus, and Porphyry on a range of topics. The analysis reveals a multifaceted use of philosophical material by Gregory that eludes a clear definition.