The Basic Kalaam Argument

1. Whatever has a beginning has a cause of its existence. (Premise)
2. The physical cosmos (=the sum total of all physical reality) has a beginning. (Premise)
3. So, the physical cosmos has a cause of its existence. (By 1 and 2)
4. The cause of the physical cosmos is not physical (on pain of circularity). (Premise)
5. So, the physical cosmos has a non-physical cause. (By 3 and 4)

The Physics Argument for 2

1. According to our best science, the physical cosmos has a beginning. (Premise)
2. What our best science says is likely true. (Premise)
3. So, it’s likely that the physical cosmos has a beginning. (By a and b)

The Finitism Argument for 2

1. There cannot be an infinite number of items. (Premise)
2. If the physical cosmos has no beginning, there are infinitely many past days. (Premise)
3. So, the physical cosmos has a beginning.

The Successive Addition Argument for 2

1. If an infinite past is possible, then someone could have been counting down from infinity and finishing today.
2. Necessarily, if someone were counting down from infinity and finishing today, there would be no explanation for why they finished today.
3. So, an infinite past is impossible.