6.However， self-fulfillment is important to morality because unfulfilled citizens， (no matter how virtuous)， can not perform the duties morality assigns them.
结构：共有2个谓语动词，其中is是主句的谓语动词。because引导原因状语从句。(no matter how virtuous)是插入语，分隔了从句的主语和谓语。拆分为：
1) Self-fulfillment is important to morality.
2) Because unfulfilled citizens can not perform the duties morality assigns them.
翻译：然而，自我实现对于道德而言至关重要，因为没有自我实现的公民，无论多么有道德，都无法履行道德赋予他们的义务。