وأما الإنّي: فهو الذي يكون الأوسط فيه علة للحكم في الذهن فقط، ولم يكن علة في الواقع، بل قد يكون معلولا له
Innī demonstration uses a middle term that grounds the judgment in the mind only, not the occurrence of the predicate in reality; it may even be an effect of what it indicates.
A reason in the mind only does not mean a fantasy or unsupported guess. It means that the middle term is our evidence for the conclusion, not its producing cause.
Thus in innī demonstration, what establishes our knowledge and what produces the reality known are different.