Before giving a brief summary in the post to follow of what I believe Zhuangzi’s position on the character of human nature is, it might be helpful to suggest what it is not, whatever its character. “Human nature” does not mean “innate nature” (hsing/xing), a term that is not found in the Inner Chapters of the Zhuangzi or the Laozi, and only appears in the 3rd Century BCE. The difference is that the former speaks phenomenologically—it is descriptive of the human expression—the latter is essentialist—it reifies the human self-experience, makes it a something, and gives us something to believe in.
Does this matter practically? Perhaps not; but since I personally understand Zhuangzi’s entire vision as pivoting on radical non-dependence on any fixed reality or idea, this belief, should it become the object of self-cultivation—an attempt to discover or realize one’s “true nature”—then it can only serve to hinder his appeal to complete openness (=emptiness).
Human nature is how we behave, not what we essentially “are”.