فإنه إنما يدل على ثبوت النقطة، وهو لا يستلزم ثبوت الجزء
It establishes at most a point, and the existence of a point does not entail the existence of an atom.
The objection identifies a shift from the kind of entity established by geometry to the kind asserted in metaphysics. A geometric point is not interchangeable with a physical or kalām substance.
The atomist still needs a further premise: every true contact must be realized through an independently subsisting indivisible material unit. The definition of an ideal sphere alone does not establish that premise.