Keynote, European Peace Research Association – Tromsö, Norway, 7 Sep 2015 Epistemology is the branch of philosophy dealing with valid knowledge; and the focus of this conference is peace in Europe. We live in a wonderful world blessed with many civilizations each with an epistemology, and in a continent with rich diversity. My task is to draw on some of this, and apply it to the peace politics of Europe. René Descartes, in Discours de la Méthode, Leiden 1637, had four basic rules; accepted, mainly unwittingly, by (North)Western science: 1. never to accept anything for true not clearly known to be such; 2. to divide difficulties examined into as many parts as possible; 3. start with the simplest and easiest, ascend to the more complex, pay attention to the asymmetric relation of antecedence and sequence; 4. make enumerations and reviews to assure that nothing was omitted. Giambattista Vico, in Scienza...