Abstract: As the main representative of truth pluralism, functionalism claims that truth is a functional property, which can be manifested by lower-level properties of different domains. Therefore, truth is both "one" and "many". There is an asymmetric manifestation relation between low-level properties and truth. Low-level properties can manifest truth, or truth is immanent in low-level properties. It can be seen that "manifestation" is an important concept of functionalism, and the manifestation relation serves as a link between "one" and "many", but this relation has also been questioned.