14. Before we can have any tolerable knowledge of this kind, we must First know what changes the primary qualities of one body do regularly produce in the primary qualities of another, and how. Secondly, We must know what primary qualities of any body produce certain sensations or ideas in us.
14. Guk mota horretako ezagutza onargarririk eduki ahal izan aurretik, beste hau ezagutu beharra daukagu, alegia, gorputz baten lehen koalitateek beste gorputz baten koalitateetan zer nolako aldaketak eragiten dituzten erregularki, eta nola. Bigarrenik ezagutu behar dugu edozein gorputzen zein lehen koalitatek eragiten dituen sentipenak edo ideiak gure baitan.