According to Gue?non, the concept 'infinite number' is a contradiction in terms. Infinity is a metaphysical concept at a higher level of reality than that ofquantity, where all that can be expressed is theindefinite, not the infinite. But although quantity is the only level recognized by modern science, the numbers that express it also possess qualities, their quantitative aspect being merely their outer husk. Our reliance today on a mathematics of approximation and probability only further conceals the 'qualitative mathematics' of the ancient world, which comes to us most directly through the Pythagorean-Platonic tradition.