As the perception of numbers is in time alone, and therefore cannot be represented by a sensuous schema like the geometrical figure, the suspicion that perception is merely empirical, and possibly illusive, disappeared in arithmetic, and the introduction of the logical method of proof into geometry was entirely due to this suspicion.
Zenbakien begiespena denboran bakarrik izaten denez gero eta horregatik ezein eskema sentigarriz, figura geometrikoa bezala, errepresentatu ezin daitekeelarik; desagertu egin zen hemen begiespena enpirikoa soilik dela eta horregatik begitazioaren mendean dagoen susmoa; susmo hori frogapen-era logikoak geometrian bakarrik sartu ahal izan du.