These following Ancient Greek Words are what I deem the basis of modern psychology.
Nous:
The Greek word noûs (νοῦς) translates to mind, intellect, or spirit. In ancient Greek philosophy, it refers to the highest faculty of the human soul responsible for grasping truth, rational thought, and intuitive understanding.
Thanatos
The Greek word Thanatos (Ancient Greek: Θάνατος, pronounced THAH-nah-tos) translates literally to “death”. It can refer to physical demise, the end of life, or—in a mythological context—the divine personification of peaceful death.