The European Physical Society Conference "Notions of Physics in Natural Philosophy" was held in 23-25 September 2007 in Athens. It was organized by the Program of History and Philosophy of Science of the Institute for Neohellenic Research / National Hellenic Research Foundation and the Laboratory of Science Education, Epistemology and Educational Technology of the University of Athens. The Conference was supported by the History of Physics Committee of the European Physical Society and the History of Physics Group of Institute of Physics (England). The latter was represented by Mr. Malcolm Cooper, editor of the Newsletter of the Group who kindly gave as a brief description of the activities of the Group.The main themes of the Conference were:i The emergence of notions of physics in ancient philosophyi The concept of physical laws in Philosophy of Nature during the Middle Ages and the Renaissancei The mathematization of Natural Philosophy and the emergence of classical sciences.We hope that the present volume of the Proceedings will be a useful tool for those interested on the subject.