Edwin Arthur Burtt on Motion

“The motions of the heavenly bodies could be charted according to Ptolemy just as correctly as according to Copernicus.”

“Newton... not only found a precise mathematical use for concepts like force, mass, inertia; he gave new meanings to the old terms space, time, and motion, which had hitherto been unimportant but were now becoming the fundamental categories of men's thinking.”

“Nicholas of Cusa... dared to teach that there is nothing at all without motion in the universe — the latter is infinite in all directions, possessing no centre — and that the earth travels its course in common with the other stars. That this widening of the intellectual horizon of the age, with the suggestion of new centres of interest, was a decisive factor in Copernicus' personal development, the brief biographical sketch which he gives of himself in the De Revolutionibus strongly suggests.”