Final answer:
Plato was influenced by Socrates, the Sophists, Ionian scientists, and the Milesians, as well as the Pythagoreans.
Step-by-step explanation:
Plato was influenced by several key figures in his philosophical development. One of his major influences was Socrates, who became the central figure in many of Plato's dialogues. Plato also learned from the Sophists, the Ionian scientists, and the Milesians. Additionally, he incorporated ideas from the Pythagoreans and other great minds of his time. Aristotle, Plato's most prominent student, later founded his own school and diverged from his teacher's ideas. Aristotle emphasized the importance of the empirical world and believed that through sensory experience and reason, one could obtain genuine knowledge.
In The Republic, Plato introduced the concept of the philosopher-kings, a political theory that has been influential through the ages. This idea emphasized the importance of rulers being wise and versed in philosophical thought.