The title is meant to tease the reader and attract his/her curiosity, but the question behind the teasing is serious. The reader will gently excuse the unconventional gait of a chapter that originated as an invited lecture given in Paris, at the HOPOS 2006 June conference. Doing philosophy of science requires having been trained both in philosophy and in (at least some) science. That is already a challenge. Studying the history of philosophy of science (which is what "hopos" means) might require having been trained as a historian as well. As life is short, and no one is omniscient, philosophy of science and its history can only be the endeavour of a community of researchers. A common endeavour calls for, if not a plan, at least a common rationality. What follows is about doubts and hopes, and about the reasons we have for tolerating, and even loving, a variety of styles in the ways philosophy of science is practiced.
