Atheism and the existence of peanut butter

[polymath257]

And my claim is that this is impossible. Causes happen *within* the universe. that means the universe as a whole is uncaused.

You are simply begging the question. You can't just assert that the universe is uncaused, you should prove that it's eternal, for example.

But nobody knows if it is eternal or not. But the nature of causality forces it to be uncaused (unless it is in a multiverse, in which case the multiverse is uncaused). There is simply no evidence to support either conclusion.

My *point* is that logic alone cannot establish that the universe is only finitely old.  It is *logically* possible to have a universe that is infinitely old. it is also possible to have a universe that is only finitely old and uncaused.

If the universe is not eternal, then there has to be some cause or reason for its coming into being. I don't know what's your stance on the principle of sufficient reason. Basically, the universe needs a reason for its existence, like any other contingent entity or object. There are many philosophers who don't accept the PSR, though.

I think the whole notion of contingent existence (as opposed to necessary) is a philosophical mistake. Contingency is just another word for being caused. But as such, it is not an opposite of necessity (it is quite possible to have uncaused events that are not necessary, at least logically. Also, probably in practice with quantum events).

My position is that the universe is not caused since causality only makes sense once things exist.

Again, you just state it cannot happen. But if an infinite amount of time has already elapsed at any point in time (which is what happens if there is no beginning), then your claim fails.

An infinite amount of time CANNOT elapse, otherwise it would be finite. QED.

That seems to be begging the question and to be a serious misunderstanding of the infinite. To elapse does NOT require the elapsed time be finite, contrary to your claims. Why is it not possible for an infinite amount of time to have already passed? No beginning, just existence at all times with caused going forward in time?

As a model, consider the negative integers. There is no first one. The interval between any two is always finite. But the total length is infinite.

Why cannot that model be one for an infinite past? This also works as a model for an infinite regress of causes.

And I agree. But that doens't mean non-classical logics don't exist and cannot be useful.

Sure. There might be other kinds of logic that proved to be useful. But if classical logic describes the workings of our world accurately enough, we don't need more.

And that is a matter of observation and testing, not of pure logic. if, for example, it turns out to be more useful to use a different logic, then would you agree we should change?

Or, for example, in intuitionist mathematics, is the denial of the law of excluded middle really a loss in the case when we are studying the infinite?