This paper deals with the moral metaphor system in general, and five pairs of MORAL and IMMORAL metaphors in particular, which are manifested in both English and Chinese. In fact, these moral metaphors are used worldwide and may even be universal. The reason for examining these pairs is that the source concepts of these metaphors display a range of opposite categories according to our visual experience, i.e. WHITE and BLACK, LIGHT and DARK, CLEAR and MURKY, CLEAN and DIRTY, PURE and IMPURE. In addition, these metaphors are further analyzed to discover whether they are primary or complex, as well as the status they enjoy, by adopting a decompositional approach. The findings show that the moral metaphors of this study tend to be complex rather than primary and that their status is not the same, since the understanding of some of them depends on the meaning of others. If this finding is validated, it can be concluded that: (1) conceptual metaphors have varying degrees of relevance; (2) the more significant a metaphor is, the more universal it becomes. Furthermore, further hypotheses can be formulated if additional thorough analyses of metaphors’ conceptual composition are performed.