 Nevertheless, when the tidal argument is added to the earlier telescopic observations that show the improbabilities of the older celestial picture—the fact that Venus has phases like the moon and so must revolve around the sun; the principle of the relativity of perceived motion which neutralizes the physical arguments against a moving Earth; and so on—it was enough for Galileo to believe that he had the necessary proof to convince the doubters. Unfortunately, it was not until after Galileo’s death and the acceptance of a unified material cosmology, utilizing the presuppositions about matter and motion that were published in the Two New Sciences, that people were ready for such proofs. But this could occur only after Galileo had changed the acceptable parameters for gaining knowledge and theorizing about the world.