The point here is that the assertion of those who say, “The constituent particles of the world must either be joined together or separated,” and so forth, rests on this principle. They consequently committed themselves to the view that all animals, plants, and minerals that come into being, and all that perish, do so solely through the joining and separation of these particles. Thus, what comes into being is the attributes of the particles, not any concrete entity.

They denied that bodies transform into one another, saying:

“The particles of semen remain in the human being, just as the particles of the seed remain in the tree. Their number has merely increased through the addition of particles from nourishment, such as particles of water and air. These particles, too, remain: they have neither been transformed nor ceased to exist, but are joined together at one time and separated at another.”

The vast majority of rational people disagree with these thinkers and affirm that bodies transform into one another. Scholars of religious law, scholars of natural science, and other groups of people are unanimous on this point.

Thus they ask: Does an impure substance become pure through transformation, or does it not? If carrion, blood, or pork turns into ash, earth, salt, or the like, scholars hold two well-known opinions concerning its purity. The view that it becomes pure is held by most jurists: it is the position of the followers of Abū Hanīfa and the Zāhirīs, and one of the two positions within the schools of Mālik and Ahmad ibn Hanbal. They agree that wine becomes pure if it transforms and changes without deliberate human intervention.

Physicians, along with everyone else, know that water turns into air, air into water, fire into air, and air into water, as