Skepticism

The Causal Argument

God

And now I seem to discover a path that will conduct us from the contemplation of the true God, in whom are contained all the treasures of science and wisdom, to the knowledge of the other things in the universe. For, in the first place, I discover that it is impossible for him ever to deceive me, for in all fraud and deceit there is a certain imperfection… and such, accordingly, cannot be found in God…

-Descartes, Meditations

St. Thomas Aquinas

Aquinas’ Causal Argument

It is therefore impossible that in the same respect and in the same way a thing should be both mover and moved, i.e., that it should move itself. Therefore, whatever is moved must be moved by another. If that by which it is moved be itself moved, then this also must needs be moved by another, and that by another again…

Aquinas’ Causal Argument

…but this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover, seeing that subsequent movers move only inasmuch as they are moved by the first mover; as the staff moves only because it is moved by the hand. Therefore it is necessary to arrive at a first mover, moved by no other; and this everyone understands to be God.

-Aquinas, The Five Ways

The Causal Argument

Part 1

1) Everything has a cause.

2) Nothing causes itself.

3) [So] Everything is caused by something else.

The Causal Argument

Part 2

3) Everything is caused by something else.

4) If (3), then either (a) there is an infinite series of causes or (b) there is a first cause.

5) There can’t be an infinite series of causes.

6) [So] There is a first cause.

The Causal Argument

Part 3

6) There is a first cause.

7) [So] God exists.

The Causal Argument

1) Everything has a cause.

2) Nothing causes itself.

3) [So] Everything is caused by something else.

4) If (3), then either (a) there is an infinite series of causes or (b) there is a first cause.

5) There can’t be an infinite series of causes.

6) [So] There is a first cause.

7) [So] God exists.

The Causal Argument

1) Everything has a cause.

2) Nothing causes itself.

3) [So] Everything is caused by something else.

4) If (3), then either (a) there is an infinite series of causes or (b) there is a first cause.

5) There can’t be an infinite series of causes.

6) [So] There is a first cause.

The Revised Causal Argument

1) Everything that has a beginning has a cause.

2) Nothing causes itself.3) [So] Everything that has a beginning is

caused by something else.4) If (3), then either (a) there is an infinite

series of causes or (b) there is a first cause (which does not itself have a beginning).

5) There can’t be an infinite series of causes.6) [So] There is a first cause (which does not

itself have a beginning).