Kalam Argument, part 2

Here again is my Pruss-inspired version of the Kalam argument, relying on causal finitism:

P1. Every event has a finite causal history (no causal loops or infinite regresses).
P2. For everything that begins to exist (at some point in time), the event of its beginning to exist must have a cause.
P3. Every non-eternal thing began to exist at some point in time (since the past of each non-eternal thing is finite in length).
P4. If the yy cause the xx to begin to exist at t, then the yy exist at t or at some time earlier than t or eternally. 
Therefore, every non-eternal thing is ultimately caused to exist by some eternal (godlike) thing.

There is, however, a problem with premise P3. Causal finitism alone does not seem to give us a finite past, not even a finite history for a given thing. 

​Suppose that we have a thing x that exists in time and suppose that causal finitism is true. This means that each event in the history of x must have a finite causal history. Is this enough to entail that x must have begun to exist at some point in the past? Couldn’t the history of x begin with an event or state that is infinitely extended in the past direction? Let’s call such an initial state a simple infinitely long past state or SILPS.
 
We can refute the possibility of a SILPS by posing a dilemma: either time itself has an intrinsic measure (in which sense time can pass in the absence of change) or it does not. If time does not have an intrinsic measure, and the initial state of x is a simple state, without discrete parts, then that state cannot have any temporal duration, much less an infinite duration (since there are, ex hypothesi, no changes concurrent with this state by which time could be extrinsically measured). Hence, we must suppose that time itself has an intrinsic measure.
 
However, this is also inconsistent with a SILPS, since if time has an intrinsic measure, then any extended period of time has discrete proper parts corresponding to the measurable proper parts of that period of time. If an event or state has a duration corresponding to that extended period, then it too must have temporal parts corresponding to the proper parts of the period of time. Thus, the state is not simple or “uneventful” after all. This is a strong argument, although it will not persuade those who think that extended simples (like extended Democritean atoms) are metaphysically possible.
 
Here is a version of the argument without the assumption of a finite past (P3):
 
P1. Every event has a finite causal history (no causal loops or infinite regresses).
P2. For everything that begins to exist, the event of its beginning to exist must have a cause.
P3.1. If something has existed for an infinite period of time, then it must have an infinite causal history (because a simple infinitely long past state is impossible).
Therefore, every non-eternal thing is ultimately caused to exist by some eternal (godlike) thing.
 
Since my argument for P3.1 is less than ironclad, I will argue in future posts both for causal finitism and for the finitude of the past of each temporal thing. This provides support for both arguments: the original argument (which depends on both causal finitism and the finite duration of the past) and the revised argument (which depends on causal finitism and the impossibility of SILPS).