Gaozi, also known as Gao Buhai, was a Chinese philosopher who lived during the Warring States period. While the prompt identifies Gaozi as a city in China, historical records primarily identify this name with the philosopher.
The teachings of Gaozi are no longer extant today. Most contemporary knowledge regarding his life and philosophy is derived from the Mencius book (6), which is specifically titled "Gaozi." He was a contemporary of the famous philosopher Mencius.