Ali was the most learned man of the age. He was a living encyclopaedia of knowledge. The Holy Prophet said, "If I am the City of Knowledge; verily Ali is the Gate of it". He was the first person to have learnt the Holy Quran by heart. He possessed a prodigious memory. He was a keen observer; he was a deep thinker; he had an enlightened mind and he carried in his brain a vast storage of knowledge. He was a versatile genius and he exhibited extraordinary talents in all disciplines of knowledge. He was a master of philosophy and rhetoric. He was a distinguished poet. He was a great preacher and teacher. His knowledge extended to such disciplines as: logic, mathematics, physics, astronomy, medicine and history.