There are many problems about causality and identity in Humeanism. Especially, a problem that “Humean Supervenience” allowing many possibilities of various external laws encounters is concerned with the difficulty whether such laws can be coherent with the intrinsic properties of causation. This problem is related to another one whether “Humean Supervenience” is compatible with objectivism in accordance with Hume's original intention. Struggling with a disharmony between Hume's pragmatic epistemology and his realistic ontology, many philosophers have tried to dissolve such a complicated problem. But I think their efforts wouldn't be successful and the disharmony doesn't need to be settled, because the prospective collapses of their efforts wouldn't reduce the meaning of Humeanism. In this paper, I conclude that the seeming incoherence should be retained, because it suggests a moderate scientific attitude to be placed between dogmatism and skepticism. I demonstrate it by emphasizing the significance of some parts included in Hume's Treatise.