Knowledge is of two kinds: that which is absorbed and that which is heard. And that which is heard does not profit if it is not absorbed.
Ali ibn Abi Talib
“Knowledge is of two kinds: that which is absorbed and that which is heard. And that which is heard does not profit if it is not absorbed.”
What does Ali ibn Abi Talib mean?
This wording is in Nahj al-Balaghah, the collection of sayings attributed to ‘Ali compiled by ash-Sharif ar-Radi (d. 406 AH / 1015 CE) without chains of transmission. Older books know the idea as a verse about the intellect rather than knowledge — “I saw that intellect is of two kinds, inborn and heard” — which al-Ghazali quotes as ‘Ali’s in the Ihya’, while al-Mawardi traces the thought to the Persian king Shapur and says a poet put it into verse. Read it as wisdom long attached to ‘Ali’s name rather than an established saying of his.
Written from Written from Al-Mukhtasar fi at-Tafsir and Tafsir Ibn Kathir.