 Avicenna’s own argument against the separateness or immateriality of mathematical objects can be summarized as follows: There are some mathematical objects in the sensible world. Otherwise, we could not grasp their concepts (e.g., the concepts triangle, circle, two, etc.) (Avicenna [MPh]: sec. VII.3, sec. 1). Now, if there are also some fully separate mathematical objects (entirely detached from the sensible world), then these two groups of (sensible/non-separate and non-sensible/separate) mathematical objects must share similar essences and definitions (Avicenna [MPh]: chap. VII.3, sec. 2). Otherwise, there is no way we can know separate material objects. This is because it does not seem that we have any direct access to a realm of fully immaterial mathematical objects (This reminds us of Benacerraf’s (1973) epistemological challenge to mathematical Platonism). Even if such things exist, we know them only through the mediation of knowing their sensible counterparts. We have no justification for the existence of separate mathematical objects which have no sensible counterpart in the material world. But this leaves unjustified the claim that mathematical objects can essentially be immaterial and separate. Avicenna takes this argument as establishing that  (SM)  is implausible (Avicenna [MPh], chap. VII.3, sec. 3; Zarepour 2019: sec. 5). We will later see that this argument reveals interesting aspects of Avicenna’s accounts of the epistemology and ontology of mathematics.