Abstract
The basis of Islamic alchemy and matter theory is found in the works of Jābir ibn Ḥayyān (d.
200/815). Jābir developed an element theory similar to Aristotle’s system. Still, he interpreted matter
and substance differently by transferring the basis of the theory from elements to qualities. In Jābir’s
system, qualities are more often expressed by the term “natures” (ṭabā’iʻ). In Jābir’s thought, four na-
tures precede the four elements, and due to the combination of two different natures with the sub-
stance each time, four distinct elements with different qualities occur. In Jābir, the “primary bodies”
of the natural world are no longer the four Empedoclean elements but the “four natures”; air, water,
earth, and fire are made up of these natures. Thus, Jābir gave the four primary Aristotelian qualities the
role of genuine elements by making them tangible, independent, and corporeal entities. According to
Jābir, the operation of transforming (transmutation) of ajsād (‘bodies’) such as iron, copper, tin, and
lead, which is the primary purpose of the Art of alchemy, into silver and gold is carried out within the
framework of the science of mīzān. The core of this transformation is based on an idea of causality in
which the four natures and their specific proportions and measures are at the center. With the idea
of causality that allows chemical transformation, Jābir also succeeded in extending the possibility of
transformation in alchemy from the inorganic world to the organic world to an extensive range of
entities. This study will discuss Jābir’s thoughts on body, substance, and experimental causality by ex-
amining Jābir’s corpus through primary sources.