While he was instrumental in the academic exploration of his techniques (he compiled two treatises: the later one in five volumes was substantially complete when he died and was published posthumously), and was himself a master of music analysis, he considered the development and study of techniques a means to intellectual, aesthetic, and emotional ends. Thus Messiaen maintained that a musical composition must be measured against three separate criteria: it must be interesting, beautiful to listen to, and it must touch the listener.