One of their most famous spats concerned the inverse square law of gravity with Hooke aggressively claiming priority for its discovery and demanding that Newton acknowledge this in the Principia, which he was in the process of writing. Now it should be clear from this story that neither Newton not Hooke could lay claim to being the father of the inverse square law of gravity as it was obvious from the original coffee house discussion that this hypothesis was common currency in the then astronomical community. In his version of the Keplerian astronomy Boulliau argued that if this force existed it would not diminish in direct inverse ratio but in the inverse squared ratio and thus the law of gravity first saw the light of day.