For, it would be very strange, that a man should allow it for an undeniable truth, that two angles of a figure, which he measures by lines and angles of a diagram, should be bigger one than the other, and yet doubt of the existence of those lines and angles, which by looking on he makes use of to measure that by.
Oso harrigarria litzateke, izan ere, norbaitek berak diagrama baten angeluen eta lerroen bidez neurturiko irudi baten bi angeluak bata bestea baino handiagoak direla egia ukaezintzat onartu ondoren, neurketa egiteko gainean ipini eta erabili dituen lerro eta angelu horien existentzia zalantzatan jarriko balu.