The sphere touches the plane in one point only: A mathematical problem?

In his commentary on Aristotle's De anima Blasius of Parma (15th century) inquires into the nature of the contact of a sphere and a plane : can it be a point ? Blasius sets himself within the framework of Aristotelian natural philosophy, which leads him to raise the question of the real existence of the point, the plane and the sphere. But the question of contact comes up again in mathematics. Blasius goes on to establish peculiar links between the mathematical problem and physical reality. This example is typical of a period (14th and 15th centuries) that saw many attempts to articulate mathematics and natural philosophy.