Perens poses "Open Source" as a means of marketing the free and open-source software idea to business people and mainstream who might be more interested in the practical benefits of an open source development model and ecosystem than abstract ethics. He states that open source and free software are only two ways of talking about the same phenomenon, a point of view not shared by Stallman and his free software movement. Perens postulated in 2004 an economic theory for business use of Open Source in his paper "The Emerging Economic Paradigm of Open Source" and his speech "Innovation Goes Public". This differs from Raymond's theory in "The Cathedral and the Bazaar", which having been written before there was much business involvement in open source, explains open source as a consequence of programmer motivation and leisure.