Latency and manifestation (kumun), al-Nazzam's doctrine

Latency (kumun) is a doctrine of natural philosophy held by the Mu'tazili Abu Ishaq Ibrahim ibn Sayyar al-Nazzam: things exist in bodies before they appear, and what is seen as newly occurring is only the appearance of what was latent. ^{4 2} The fullest account of it among the sources read here is the one his pupil al-Jahiz gives at the start of the fifth part of Kitab al-Hayawan, within the discussion of fire. ⁵ This is an account of a Mu'tazili theological doctrine; the Sunni position on it, as 'Abd al-Qahir al-Baghdadi states it, is given first below.

In al-Farq bayn al-Firaq, 'Abd al-Qahir al-Baghdadi (d. 429 AH) counts al-Nazzam's doctrine of manifestation and latency in bodies and their interpenetration among his scandals. He calls it worse than the view of the Dahriyya, who claimed that all accidents lie latent in bodies, and says each of the two doctrines opens a way for the Dahriyya to deny that bodies and accidents are originated, since both claim that all of them exist at every moment, some latent and some manifest; he describes this as heresy (ilhad). ³ He connects it with what he calls the fourteenth scandal: al-Nazzam's claim that God created people, beasts, plants and minerals all at one time, that the creation of Adam did not precede that of his children, and that priority and lateness lie only in their emerging from their places. He says this goes against what the early community agreed upon, and against most of the Mu'tazila as well. ^{6 3}

Al-Jahiz begins with al-Nazzam's statement that fire is a name for heat and light, that burning and warming belong to one of these two interpenetrating kinds, namely heat, and that heat is a substance that rises. ⁵ He then reports his argument for fire being latent in stone and wood: whoever denies it must also say there is no oil in sesame and no oil in olives, and that blood was not in a man but came into being when he was cut. ⁴ He reports that wood, when its parts break up, returns to four things — fire, smoke, water and ash — and so is composed of them, just as pottery is earth, water and fire, except that the one is put together by human beings and the other by God. ^{1 7}

In al-Jahiz's summary, the burning of cloth, wood and cotton is only the coming-out of their own fires, not fire arriving from somewhere to act on them: the latent fire could not overcome its opposite, but when it met another fire the two together overcame the obstacle and it appeared. Al-Nazzam extends this to the heat of the sun, to the viper's venom, which kills by aiding the poisons latent in the body, and to the faintness that overcomes a person in the bathhouse. ²

Al-Jahiz names three lines of disagreement. The first is Dirar ibn 'Amr, who held that the affirmation of God's oneness is sound only if latency is denied; al-Nazzam answers that Dirar knew for certain that the inside of a man is never without blood. ¹ The second is the "people of accidents", who said that when two sticks are rubbed the air between them heats and turns into fire, so that fire is transformed air, air being close kin to fire; al-Nazzam holds them to saying the same of the water, smoke and ash that come out of wood. ^{8 9} The third asked why, if heat were in wood, one who touched it would not feel it; al-Nazzam replied that the cold prevailing in the lower world draws off the wood's cold once its obstacle is gone, resorting here to the doctrine of the "leap" (tafra); al-Jahiz comments that his opponent then has no choice but to open a new question refuting the leap. ^{10 2}

Al-Jahiz says what he has set out is "one chapter of the discussion of fire", and that he must give "both parties" their full due. ⁹