 Some of the implications of tahqîq can be understood when it is contrasted with its conceptual opposite, taqlîd, which means imitation or following authority. Knowledge can be divided into two sorts, which in Arabic were often called naqlî, transmitted, and ‘aqlî, intellectual; or husûlî, acquired, and hudûrî, presential. Transmitted knowledge is everything that one can learn only by imitating others, like language, culture, scripture, history, law, and science. Intellectual knowledge is what one comes to know by realizing its truth within oneself, like mathematics and metaphysics, even if these are initially learned by imitation. Mullâ Sadrâ calls intellectual knowledge “non-instrumental” (al-ghayr al-âlî), because it accrues to the soul not by the instruments of sense perception, imagination, and rational argumentation, but by the soul’s conformity with reason or intelligence (‘aql), which, in its fullest reality, is nothing but the shining light of the Real. In short, Ibn ‘Arabî, like many of the Islamic philosophers, holds that real knowledge cannot come from imitating others, but must be discovered by realization, which is the actualization of the soul’s potential. Ibn ‘Arabî differs from most philosophers in maintaining that full realization can only be achieved by following in the footsteps of the prophets.