Thomas Aquinas Latin version of Aristotle corpus arrives in Europe. Aquinas pours over it. Aquinas basically is responsible for the ‘rebirth of reason’ Aquinas: God leads humans to a rational and moral life Aristotle: Rationality and morality are inherent qualities in humans.

Aquinas on Knowledge A) Man can know of the world only that which he learns from experience but this sets limits to what can be known: How can reason and faith be reconciled. B) The world is intelligible to the rational man. Whatever exists can be understood and has a set of causes. These causes can be known through experience and (rational) reflection.

Roger Bacon There two ways of acquiring knowledge, one through reason, the other by experiment. Argument reaches a conclusion and compels us to admit it, but it neither makes us certain nor so annihilates doubt that the mind rests calm in the intuition of truth, unless it finds this certitude by way of experience.

Roger Bacon Even if a man that has never seen fire, proves by good reasoning that fire burns, and devours and destroys things, nevertheless the mind of one hearing his arguments would never be convinced, nor would he avoid fire until he puts his hand or some combustible thing into it in order to prove by experiment what the argument taught. But after the fact of combustion is experienced, the mind is satisfied and lies calm in the certainty of truth. Hence argument is not enough, but experience is.

Towards Real Science In 1328 or earlier, Ockham, in Summa Logicae, wrote that universals exist only in men's minds and in language, disputing the Aristotelian principle that such things as the final cause were self-evident or necessary. In other words, facts could only be correlated, not caused. Ockham's razor: ‘What can be done with fewer assumptions is done in vain with more’. Does this represent a Bias?

 Jean Buridan, supported that motion was maintained by some property of the body, imparted when it was set in motion..  Buridan further held that the impetus of a body increased with the speed with which it was set in motion, and with its quantity of matter. Buridan anticipated Newton by 300 years when he wrote:...after leaving the arm of the thrower, the projectile would be moved by an impetus given to it by the thrower and would continue to be moved as long as the impetus remained stronger than the resistance, and would be of infinite duration were it not diminished and corrupted by a contrary force resisting it or by something inclining it to a contrary motion  This theory of impetus was also adapted to explain circular motion of the planets

THE MERTONIANS: MEAN SPEED THEOREM – 1330S The law states that a body travelling at constant velocity will cover the same distance in the same time as an accelerated body if its velocity is half the final speed of the accelerated body. Distance = velocity*time = vt Velocity = acceleration*time = at v = at; d=vt  d =at 2 (Muslim algebra) Mertonian concept: Average velocity = (1/2) * (initial velocity + final velocity) V –initial = 0  average velocity = ½*V-final Therefore, d = ½ at 2 for object initially at rest Experimentally determined by Galileo

Nicole Oresme Circa (University of Paris) Probably the first example of what we would consider as a modern scientist – proved the mean speed theorem Paris master and bishop of Lisieux who reformulated Aristotle's doctrine of natural place in a way that allowed for the possibility of other worlds. He taught that the doctrine was valid providing only that heavy bodies were located more centrally than light ones. Since there could be many centers, there could, in principle, be many different systems of worlds

Oresme Continued Associated the idea of continuous change with a coordinate system (long before Descartes) Gave credible opposition to the idea of an unmoving Earth: “if a man in the heavens, moved and carried along by their daily motion, could see the earth distinctly..., it would appear to him that the earth is moving in daily rotation "