I recently listened to this podcast episode by Malcolm Galdwell. It is about the researchers involved in the discovery of retroviruses and the paradigms they had to break through and how these scientist in the early days were thought to be crackpots. It is a story familar to any of us who follow science. I enjoyed how it was presented. Near the end, David Baltimore, who shared the Nobel prize for the discovery of reverse transcriptase, says in reference to studying a disease, The worst thing that can happen, and it was proved in the HIV epidemic, is not to know what’s causing a disease because that gives liberty to fantasy. here is one source for the podcast: http://revisionisthistory.com/episodes/40-the-obscure-virus-club