Abstract
The "thing-in-itself" theory occupies a pivotal position in the whole of Kantian philosophy, and scholars have expressed varying views on the intricate content of the theory. In the realm of epistemology, the theory implies at least three things: the origin of sensation, the limits of knowledge, and the rational idea. The last implication leads directly to moral reality in the realm of ethics. Interwoven and mutually comprehended, these implications are dipped in the general meaning of agnosticism. The first and third implications are the opposites of a "thing-in-itself," and the second is a transition from the first to the third