Final answer:
The two principal Taoist texts are the 'Tao Te Ching' by Laozi and the 'Zhuangzi', with themes of harmony, simplicity, and living in accordance with nature.
Step-by-step explanation:
The two most important works of Taoism are the Tao Te Ching and the Zhuangzi. The Tao Te Ching, attributed to Laozi, emphasizes simplicity, harmony, and following the natural way of things. It is a foundational text of Taoist philosophy. The Zhuangzi, named after its author, offers an expansion on these ideas, criticizing the artificiality of human lifestyles and promoting a life aligned with nature to overcome suffering caused by desire and greed.