Eastern philosophy
The "Dao De Jing" ("Tao-Te-Ching," c. 4th century BCE), traditionally attributed to Laozi, and the "Nan Hua Jing" ("Zhuang Zi") are considered the key texts of the tradition. The first organized form of Taoism, the Tianshi (Celestial Masters') school arose in the 2nd century CE. Xuanxue ("deep learning", also "Neo-Taoism") was a major philosophical movement influenced by Confucian scholarship, which focused on the interpretation of the "Yijing," "Daodejing," and "Zhuangzi" and which flourished during the third to sixth centuries CE. The most important philosophers of this movement were He Yan, Wang Bi, the Seven Sages of the Bamboo Grove, Ge Hong and Guo Xiang. Thinkers like He Yan and Wang Bi focused on the deep nature of Tao, which they saw as being best exemplified by the term "Wu" (nothingness, non-being, negativity).
The Three Philosophers
It has been suggested that the figure of the young man can be inscribed neatly in a right-angled triangle for which the Pythagorean theorem applies. , relying on a reading of Polydore Vergil has proposed that the philosophers are the teachers of Pythagoras - Pherecydes of Syros and Thales. Thales has been painted as a Jew, while Pherecydes was mistakenly believed to be a Syrian. This interpretation was modified by Frank Keim who claimed that the older philosopher is in fact Aristarchus of Samos