Graphology in handwriting analysis. He published his findings shortly after founding "Société Graphologique" in 1871. The most prominent of his disciples was Jules Crépieux-Jamin who rapidly published a series of books that were soon published in other languages. Starting from Michon's integrative approach, Crépieux-Jamin founded a holistic approach to graphology. Alfred Binet was convinced to conduct research into graphology from 1893 to 1907. He called it "the science of the future" despite rejection of his results by graphologists. After World War I, interest in graphology continued to spread in Europe as well as the United States. In Germany during the 1920s,
What Is and What Should Never Be descending riff [of "What Is and What Should Never Be"] is amazing: It's like a bow is being drawn back, and then it releases. The rhythm of the vocals is almost like a rap. It's insane — one of their most psychedelic songs." This was also one of the first songs recorded by the band for which Robert Plant received writing credit. According to rock journalist Stephen Davis, the author of the Led Zeppelin biography "Hammer of the Gods: The Led Zeppelin Saga", the lyrics for this song reflect a romance Plant had with his wife's younger sister. "What Is