This letter, written to Mawlânâ Muhammad Sâdiq Keshmirî, explains the difference between the ’ilm-ul-yaqîn of the men of tasawwuf and the ’ilm-ul-yaqîn of philosophers:
Hamd be to Allâhu ta’âlâ! Salâm to those slaves of His chosen and loved by Him! According to men of tasawwuf, ’ilm-ul-yaqîn means to infer the agent of the work by seeing the work. Also philosophers, who follow the way of understanding and judging everything under the guidance of the mind, are of the same opinion. What is the difference between these two? Why does the ’ilm-ul-yaqîn of men of tasawwuf get formed through kashf and shuhûd? In what way is the ’ilm-ul-yaqîn of those savants of the dîn who are not men of tasawwuf like that of philosophers? We shall explain these briefly. In both types of ’ilm-ul-yaqîn it is necessary to see the work. A path through the work will lead to the unseen doer. The path that leads man to the doer from the work is the relation between these two. In the ’ilm-ul-yaqîn
of the men of tasawwuf, this relation is seen through kashf and shuhûd, too. But in the ’ilm-ul-yaqîn of savants of the dîn and of philosophers this relation is realized through mind, by thinking and observing. For this reason, men of tasawwuf’s recognizing the doer from the work is hadsî (inductive, intuitive). That is, it happens automatically and spontaneously. In fact, it is badîhî, that is, it is obvious, quite clear. But the others’ inferring the doer by seeing the work is by thinking, observing. As it is seen, the ’ilm-ul-yaqîn of men of tasawwuf is through kashf and shuhûd. But the others’ ilm-ul-yaqîn cannot be formed without observing with mind. The ’ilm-ul-yaqîn of men of tasawwuf also is called istidlâl, that is, thinking, yet
it is called so because inferring the doer from the work is given this name. In actual fact, it is not istidlâl, but it is kashf and shuhûd. The ’ilm-ul-yaqîn of savants of the dîn is through istidlâl. Many people could not understand this subtle difference. Some of them spoke ill of great men of tasawwuf. Allâhu ta’âlâ, alone, communicates the truth of every matter. May our salâm be upon those who are on the right way!