لأن اجتماعهما أي اجتماع الطرفين في شيء إما ممكن وإما ممتنع
The two terms may either coexist in one subject or be incompatible there.
When the intended states can belong together to one subject, the metaphor is called wifāqiyyah, the concordant kind. It is not necessary that the two states be synonyms; their compatibility is the decisive consideration.
When the relevant conditions exclude each other in the same respect, the figure is ʿinādiyyah, the opposing or discordant kind. Genuine existence and absolute nonexistence cannot be simultaneously affirmed of the same thing in the same respect. This classification concerns conceptual relation rather than the accidental similarity of word forms.