Of all the intellectual hurdles which the human mind has confronted and has overcome in the last fifteen hundred years, the one which seems to me to have been the most amazing in character and the most stupendous in the scope of its consequences is the one relating to the problem of motion...On this question of motion the Aristotelian teaching, precisely because it carried such an intricate dovetailing of observations and explanations--that is to say, precisely because it was part of a system which was such a colossal intellectual feat in itself--was hard for the human mind to escape from, and gained a strong hold on medieval scholastic thought...On the Aristotelian theory all heavy terrestrial bodies had a natural motion towards the centre of the universe, which for medieval thinkers was at or near the centre of the earth; but motion in any other direction was violent motion, because it contradicted the ordinary tendency of a body to move to what was regarded as its natural place. Such motion depended on the operation of a mover, and the Aristotelian doctrine of inertia was a doctrine of rest--it was motion, not rest, that always required to be explained. Whenever this motion existed, and however long it existed, something had to be brought in to account for it.
Friday, October 11, 2013
This is taken from Herbert Butterfield's The Origins of Modern Science, 1300-1800: