Atheism Cosmology Logic and First Principles of right reason Philosophy Physics

Re: The Viability of an Infinite Past

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Over in this thread, a number of us have been having a discussion with daveS regarding the alleged possibility of an actually infinite past. DaveS seems to think that an infinite past is a perfectly viable model that does not entail any logical contradictions.  Various arguments for the necessary finitude of the past were offered in that thread by myself and others, however, in comment #187 I offered the following argument for the finitude of the past that did not rely on the impossibility of an actual infinite existing in the world:

1) The past consists of moments that were once the present

2) If the past is infinite, then for any given moment there were infinitely many moments that preceded it

3) If an infinite past entails that for any given moment there were infinitely many moments that preceded it, then an infinite past entails that any moment that was at one time the present was preceded by an infinite number of prior moments already constituting the past

4) If an infinite past entails that any moment that was once the present was necessarily preceded by an infinite number of moments already constituting the past then it entails the existence of infinitely many past moments that were never the present

Therefore:

5) Either premise 1 is false and the past does not consist [entirely] of moments that were once the present, or the past is not infinite

6) Premise 1 is not false and the past does consist [entirely] of moments that were once the present

Therefore:

7) The past is not infinite

DaveS disagreed from Premise 4 on, though no specific argument was given for why Premise 4, or anything else, was incorrect or failed to follow as a matter of logical necessity. For the sake of making ongoing discussion easier to understand I’ve created a couple of simple diagrams / infographics to visualize the logic of the argument, comparing a visualization of how we typically view the flow between future, present and past with the flow seemingly required by the necessary characteristics of an actually infinite past.

First, a diagram of how we typically view the flow of time given a finite past:

Diagram-FinitePast

 

And now a diagram showing the characteristics and preconditions of an actually infinite past:

Diagram-InfinitePast

All comments on this issue can continue in the other thread after comment #274.

3 Replies to “Re: The Viability of an Infinite Past

  1. 1
    HeKS says:

    I haven’t yet figured out how to disable comments on this post but please comment in the other thread linked in the post if you wish to participate in the discussion.

  2. 2
    bornagain77 says:

    HeKS, since I am going to reference your post on facebook and in my notes, I hope it is not too much of an imposition to reference my response on your other thread here:

    The argument against an infinite regress in time of course is, and always has been, a sound one.
    Moreover, this ancient philosophical argument against an infinite regress is now empirically verified by General Relativity and the Borde, Vilenkin, and Guth theorem,,,
    http://www.uncommondescent.com.....ent-618999

  3. 3
    Barry Arrington says:

    Comments have been disabled per HeKS’ request. Comment on the other thread.

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