Development is a matter of great importance to the destiny of mankind. It directly engages everyone and indirectly involves the earth on which mankind depends and even the universe. Throughout the history of mankind, development as a whole manifests itself as a logical process, following the thread of tapping its own potential to the fullest extent, gradually demonstrating its inborn nature and going on sustainably. The logical process of development exhibits its inherent trait and follows its own nature. The essence of development is that mankind reaches the goal of displaying their true nature through following the nature of other substances, in another word, by tapping their potential to the fullest, mankind abandons innate nature to show the nature of freedom. To put it in another way, all developments are concerned with mankind. Fundamentally, development is a grand process in which the natural attributes of history of mankind continue its own self-denial and gradually realize their characteristics of freedom. In view of this, there is no simple way of achieving sustainable development in the world today. However, we can still pursue the principle of following the nature in the process of development. We ought to, in a wise way, comprehensively make use of a wide array of methods and adopt different approaches to maintain or promote sustainable development or free development, and by doing this, mankind will remain on earth, generation after generation.