1. AQUINAS (1225-1274) Aristotle is rediscovered by Christian Europe In 13 th Century

2. Aristotle Aquinas 1225 – 1274 AD 384 - 322 BCE

3. 0. Aristotle (384-322 BCE) physics god (master-slave relationship), Christianity, Islam, Toledo Aquinas, St. Louis’ crossbowmen.

4. 1. A priori vs. a posteriori rationalism vs. empiricism “ontological” argument versus “cosmological” argument

5. 2. Aquinas’ “1st way” i) Some things change (move). (Known by observation.) ii) All things that move are moved by something else. -Long Aristotelian sub-argument for ii), drawing on the logical relationship between actuality, potentiality, and change iii) The something else is also moving, and so must be moved by a third thing according to ii) iv) The chain of movers must have a first mover, otherwise there would be no motion. v) first mover = God

6. The 2 nd – 5 th Ways Same logic as 1 st way Some phenomenon, x, is observed 2 nd - causation, 3 rd - ontological dependence, 4 th - gradations of value, 5 th - natural goals It is explained by something else, y, which is explained by z,… The explanatory chain is said to demand an unexplained explainer The unexplained explainer is said to be God

7. 3. The logic of explanation i) explanandum (explainee) ≠ explanans (explainer). In other words: explanations cannot be circular. ii) explanans must entail explanandum. iii) all explanations are chains of inference. Do they need an unexplained explainer? If they do, must the unexplained explainer be God?