As a promising solution to the mind-body problem, panpsychism is the thesis that consciousness is fundamental and universal in the world. It has several theoretical advantages over other competing theories such as physicalism and dualism. Nevertheless, there is also worry that the solution to the mind-body problem is beyond our intellectual access due to our cognitive constraints, and there is no reliable reason for us to favour panpsychism over other theories despite its elegance and simplicity. In this paper, I give a substantial argument for panpsychism from an epistemic approach. I argue that if the solution to the mind-body problem is accessible to any cognitive subject, it must be a panpsychist one. I conclude that either we and any other cognitive beings can never solve the mind-body problem or panpsychist idealism is true.