The establishment of the authorship and originality of art works is a key element for enjoying art and for the correct functioning of the market and of many arts centres. As such, it is one of the tasks undertaken by all sorts of individuals and institutions, from artists' foundations to museums, from public administrations to academics, dealers and art collectors.This book, which derives from an international seminar organised by the Gala-Salvador Dalí Foundation, presents new approaches, linguistic proposals and improvements in the rules governing this matter in order to ease the disputes and conflicts of interests that usually arise in its sphere.