Abstract
We can find the origins of the notion of void in the Kalām tradition’s recognition of atomism. However,
the main debates on the subject appeared after the Greek philosophical heritage transitioned to the Islamic world
in the 3rd century of Hijra. The literature of Kalām, just as in the metaphysical tradition, has two main types for this
void being discussed. The first one is the external void (extracosmic) in which the cosmos floats. In the sources of
Kalām, the question of whether such a type of void exists is debated around the questions of whether anyone who
might look beyond the cosmos can see anything or whether someone who stretches their hand outside the cosmos
can move it. The second type of void, which occupies more of the mutakallimūn (Muslim theologians) agenda, is the
internal void (intercosmic), assumed to be within the cosmos and between the body-forming atoms. This kind of
void is discussed around the question of “Whether separating the two atoms is possible so that a third one can be
inserted between them?” An ongoing discussion on the intercosmic void is found between the Baṣran and Baghdād
Schools of Mu’tazila. Ibn Mattawayh and al-Nīsābūrī narrated the evidence presented in these discussions in their
original form. The current essay discusses the debates between the two Schools and assesses the theoretical and
experimental arguments both Schools present to justify their viewpoints, considering their philosophical origins.