Merton College sheltered a group of dons devoted to natural science, mainly physics, astronomy and mathematics, rivals of the intellectuals at the University of Paris. Bradwardine was one of these Oxford Calculators, studying mechanics with William Heytesbury, Richard Swineshead, and John Dumbleton. The Oxford Calculators distinguished kinematics from dynamics, emphasising kinematics, and investigating instantaneous velocity. They first formulated the mean speed theorem : a body moving with constant velocity travels the same distance as an accelerated body in the same time if its velocity is half the final speed of the accelerated body. They also demonstrated this theorem — the foundation of "The Law of Falling Bodies" — long before Galileo, who is generally credited with it.