Our infinite past
I argued earlier that determinism implies a beginningless past: there was no first event. Strictly speaking, we need another argument to establish an infinite past. For consider: The open real-number interval (0, 1) is beginningless in that it has no smallest member, yet it’s only finitely long. So here’s another argument:
- There’s a logically sufficient explanation for everything.
- There’s no logically sufficient explanation for time’s being infinite only toward the future or only toward the past. (Time’s “preferring” one direction for its infinitude is arbitrary.)
- Therefore: If time is infinite in at least one direction, then it’s infinite in both directions. [From 1, 2]
- If time is infinite in neither direction, then the total duration of time is finite.
- Therefore: If the total duration of time is finite, then there’s a logically sufficient explanation for its having the particular finite duration it has. [From 1]
- There’s no logically sufficient explanation for time’s having any particular finite duration. (Why that number of seconds and not some other?)
- Therefore: Time is infinite in at least one direction. [From 4‒6]
- Therefore: Time is infinite in both directions ‒ past and future. [From 3, 7]
So the past and the future are infinite. The key premise is 1: There’s a logically sufficient explanation for everything. That premise, which defines the outlook of metaphysical rationalism, is known as the “Principle of Sufficient Reason” (PSR). I accept PSR, and I bet that, deep down, you do too. Much more about all this in future posts!
