Generally speaking, a problem of this kind may occur in any other field of knowledge. For example, a point is known in mathematics as an infinitesimal circle, whereas the circle itself is defined as a set of points ordered in a certain manner. As is easy to see, these terms are defined through each other. At the same time, this "inadvertence" did not become a stumbling block for mathematics. Both circles and points go well together, as well as with other terms adopted in mathematics. Moreover, everybody understands by insight what a point is and what a circle is.