Abstract: The "negative" in Hegel's dialectics is not in the agreement with its mysterious form, but its intrinsic revolutionary elements are adopted by Engels.Hegels' logic and historical research methods are extended in Engel's natural dialectics, from the speculativeness to historical reality, thereby the status of human being is established in the "dialectics" and "nature", and the natural dialectics becomes one of the subjects of "human" philosophy, not of "spiritual" philosophy.As a practical and open philosophical discipline, the vitality of natural dialectics is rest with the speculative kernel derived from Hegel's philosophy, and even in the contemplation of natural being.