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).
Western canon
Ancient Greek philosophy has consistently held a prominent place in the canon. Only a relatively small number of works of Greek philosophy have survived, essentially those thought most worth copying in the Middle Ages. Plato, Aristotle and, indirectly, Socrates are the primary figures. Roman philosophy is included, but regarded as less significant (as it tended to be even by the Romans themselves). The ancient philosophy of other cultures now receives more attention than before the 20th century. The vast body of Christian philosophy is typically represented on reading lists mainly by Saints Augustine of Hippo and Thomas Aquinas, and the 12th-century Jewish scholar Maimonides is now usually represented, mostly by "The Guide for the Perplexed". The academic canon of early modern philosophy generally includes Descartes, Spinoza, Leibniz, Locke, Berkeley, Hume, and Kant, though influential contributions to philosophy were made by many thinkers in this period.