but if there is a demonstrative science which deals with them, there will have to be an underlying kind, and some of them must be demonstrable attributes and others must be axioms (for it is impossible that there should be demonstration about all of them);
Izan ere, printzipio bakoitza zer den badakigu jakin (beste arteak, behintzat, printzipio hauetaz baliatzen dira, hauek ezagunak bailiran).