(4) That from which, as an immanent part, a thing first comes to be, e,g, as the keel of a ship and the foundation of a house, while in animals some suppose the heart, others the brain, others some other part, to be of this nature.
Eta printzipio esaten zaio zerbait egiteko gauzaren baitan dagoen 5) abiapuntu lehenari, adibidez: itsasuntzi batena gila da;