Dr Ibrahim Kalin - The Royal Islamic Strategic Studies Centre

substantive view of rationality follows from the intrinsic
intelligibility of existence as God’s creation. Every rational
act on our part is an act of conforming to the principle of
reason built into the nature of things. Whatever violates this
principle lands us in the realm of the irrational.
Substantive rationality is also supported by the anthropology
of reason itself. Most Muslim thinkers hold that reason
responds to empirical data and abstract notions through
its own innate qualities. Far from being a hypothetical tabula
rasa, reason reflects the fundamental traits of existence of
which it is a part. Raghib al-Isfahani divides reason into two:
‘aql matbu’, “innate reason”, and ‘aql masmu’, “acquired reason”.
Masmu’ literally means that which is heard, referring to
things learnt by hearing from others. It roughly corresponds
to experience and refers to the context of human relations.
Innate reason refers to our in-born ability to grasp the intelligible
order and truth of things. It is through innate reason
that we inhabit an intelligible world. Acquired reason is what
we learn by ‘hearing’ from others and refers to the context
of social relations and linguistic forms with which we name
things.
The two are intertwined but ‘innate reason’ takes precedence
over ‘acquired reason’. Isfahani, who attributes this division
to Imam Ali ibn Abi Talib, says that just as the light of
the sun has no use when the eye is blinded, acquired reason
can do no good when innate reason is corrupted. 17 Reason
17 Raghib al-Isfahani, al-Mufradat fi gharib al-qur’an (Istanbul: Kahra-
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