Why have philosophers questioned whether people can know abstract mathematical objects?

In the philosophy of mathematics, philosophers have questioned whether humans can know abstract mathematical objects primarily due to the epistemological argument against Platonism.1

This argument is based on the following premises:
* Humans exist entirely within space-time.1
* If abstract objects exist, they are nonphysical, nonmental, and exist entirely outside of space-time.12
* Therefore, it is difficult to explain how humans could ever acquire knowledge of such objects, as there appears to be no way to establish information-gathering contact with them.1

Because abstract objects—such as perfect triangles or numbers—do not exist in the physical world, they cannot be apprehended through ordinary sense perception. While some philosophers, such as Plato and Kurt Gödel, proposed that humans possess special faculties like intuition or immaterial souls to access these objects, others remain skeptical, viewing abstract entities as "weird, occult" concepts. Consequently, this challenge has led to various alternative views, including fictionalism and intuitionism, which attempt to account for mathematical truth without relying on the existence of nonspatiotemporal objects.3124