Specialist in the study of "parasciences" (pseudoscience), he became interested in UFOs in particular therefore to ufology, but also to parapsychology and cryptozoology. Defender of sociology "irréductionniste," he believes that a sociological approach to avoiding the UFOs to consider them as "mistakes" can be provided to "start with the sociology of scepticisme2". Greater sharing refusing rational / irrational, Lagrange found that the pseudoscience are subject to both a belief shared by many, and many speeches, whether that of ufologists, skeptics ("debunkers") , journalists or armée3. Therefore, he writes that "pseudoscience does not exist" and "the irrational is an invention" because "for there to be parasciences, he would have to be science such that as described in the books and dictionaries rationalist epistemology. Hard sciences, rational, tolerant fashions and trends of society, thought right and flawless. But these sciences, it is now certain, pas3 exist. "