Sunday, November 22, 2009

Three arguments for the finitude of the past


Jesse said...

I'm not sold on this. The argument seems to be smuggling in idealist assumptions. An infinite series of time is not an actual infinite; it is an infinite series involving a finite number of actual things.

I think there's an undesirable corollary for those using this as a "proof." For could not God, who is timeless, create an infinite series of time from eternity? This "proof" seems to deny either 1) that possibility, or 2) that God is eternal.

Personally, I see no contradiction in the idea of an eternal God creating an infinite series of time... I'll have to give this some more thought though...

unkleE said...

Contrary to Jesse, I find these arguments very convincing.

Jesse, I cannot understand your statement: "An infinite series of time ..... is an infinite series involving a finite number of actual things." Can you explain it more please?

Re your "undesirable corollary", I have heard it argued that the only way an infinite series can be created is all at once (which God could conceivably do), just not one at a time, as this article argues.

I think there is another, more physics based, argument. If the universe, or a succession of universes, was infinitely old, every possible process that could have occurred would have had time to have occurred, and the second law of thermodynamics would have had more than enough time to have been effective. The universe by now would be a thin cold homogenous gaseous soup. The fact that it's not indicates that it's not that old. The only way out of this, I think (and I've seen some people argue it) is to say that perhaps in previous universes there was no time, or the second law didn't apply, all of which amount to saying that the cause of the universe is not natural as we know it, which is what the Kalam argument is setting out to prove.

Thanks for the reference, it is very useful.

Clayton Littlejohn said...

"The second mathematical argument for the claim that the universe has a beginning draws on the idea that an actual infinite cannot be created by successive addition. If one begins with a number, and repeatedly adds one to it, one will never arrive at infinity. If one has a heap of sand, and repeatedly adds more sand to it, the heap will never become infinitely large. Taking something finite and repeatedly adding finite quantities to it will never make it infinite. Actual infinites cannot be created by successive addition.

The past has been created by successive addition. The past continuously grows as one moment after another passes from the future into the present and then into the past. Every moment that is now past was once in the future, but was added to the past by the passage of time."

This begs the question. Isn't that just obvious? If "the past has been created by successive addition" that had a starting point, we're assuming a starting point. No argument there. Make it explicit that we're not assuming that there was a beginning to the process of adding moments of time and the argument goes nowhere. Suppose I take a set {x} and add a member to make a new set {y}. Suppose I construct new sets a finite # of times and the resulting set is {z}. While I've constructed {z} by successive addition, you can only then say that {z} is finite once you've established that {x} is. But, I didn't say whether {x} consists of rock bands, sea shells, or the natural numbers.

How many times do we have to see the same bad arguments? It's the same sloppy, lazy reasoning we've seen before, only this time it's from a slightly different website.