I think his view is that the universe has dualism. It is existence and thinking. This famous saying is that he admits that there is a kind of "starry sky above me" that is independent of human consciousness. However, he thinks that the "starry sky above me" itself cannot be known in principle (it is estimated that this is agnosticism). Because the form of human perception is imprisoned in space and time, it is impossible for us to realize the truth of things, and we can only know the appearance of things. That is, "the moral law in me". Although we can't understand it, people are morally independent, and although people's behavior is limited by objective cause and effect, the reason why people become people lies in their moral freedom, their ability to transcend cause and effect and their ability to be responsible for their actions. This requires "admiration and awe to fill our hearts"

Personally, I think that the "starry sky above me" he said is God, and it is also the "Tao" that Lao Tzu said. It can be understood as: after the Tao generates all things, it is contained in all things in heaven and earth as the basis for the existence of all things in heaven and earth, and the Tao is universal, all-encompassing and all-encompassing. Although Tao exists in all things in heaven and earth, it is different from tangible things that can be felt. It is invisible, deaf and irresistible, and it is something that constitutes the same essence of all things in heaven and earth. Therefore, we can't rely on sensory organs to realize it, and it is difficult to express it with ordinary words. We can only use metaphors and descriptions to illustrate its existence.

personally, I also think that his "law in me" has something in common with modern quantum mechanics: the characteristics of things are related to the observer.