It’s Turtles All the Way Down - the Infinite Regress Problem

An Infinite Regress entails the inconceivable; an actual infinity. This quantity, in different contexts, yields different answers; many of which are in contradiction.

For instance, consider 2 + 3 =5. Thus, 5 - 3 = 2

So,

Infinity + Infinity = Infinity. 

Therefore; Infinity - Infinity = Infinity

However

Infinity + 0 = infinity. Therefore, infinity - Infinity = 0; but that's different to the answer above.

There are two major forms that the infinite regress problem takes.

Epistemic Regress: Knowledge is a true, justified belief. In every chain of logical reasoning, each step depends on the previous one (its justification) for its existence. For the sake of understanding, let’s take a step T1 in a logical argument. T1 relies on T2 for its justification, and similarly, T2 relies on T3, which again would require a justification in the form of T4. T1 will never be supported adequately, because the needed series of support would be infinite, and we would never have any justified knowledge. Thus, it has been proposed that reason is the basis for knowledge.  

 
Metaphysical Impossibility: This can be explained by taking an ontological example. Things in the external world are taken to exist because of the parts that they are composed of. These things (parts) must also depend on their own parts for existence. This chain continues till infinity, which many thinkers claim to be impossible.

Everything in the world has an origin. Something cannot come from nothing. Yet, something must have come from nothing if we want to be logically coherent . The idea of an origin-less universe seems absurd. Especially in light of the scientific evidence for it.

Those who propose an infinite/infinite universe, what do you do about the problem of an infinite regress of causes?

In other words, a series of things that are each ontologically dependent on the next; in this case, the singularity, the singularity -1, the singularity -2, the singularity -3....

How do we reach the singularity if there is an infinite/endless series of causes?

For example, if a giraffe had an infinitely long neck, he would die of starvation - even if he had eaten for an infinite amount of time - since the food would always have another inch to travel before it reached the stomach. So this string of infinite causes would always have another casual step to take before the singularity happened.

To say that "that there is no first moment, because every moment is preceded by earlier moments" is to be logically and philosophically hanging in midair.

Christians would say that God is a metaphysically necessary [efficient] cause for the material universe, thus avoiding regress problems.

Infinite regress can be a problem because it can lead to answers that never terminate. When people ask for justification for something, they want an answer that is compelling. However, answers that result in an infinite regress aren't rationally compelling

It’s more logical to believe in an uncreated Creator or First cause than an infinite universe. Why? Because If God had a creator [or a cause had a cause] who brought Him into existence, then we could ask “who created that God?” 

Ockam’s Razor - the philosophical principle used in science that suggests you shouldn’t multiply causes to explain something beyond what’s necessary - would suggest that we not have a regression of creators at all. The one who brought our universe into being is the uncreated one.

This isn’t special pleading for God. This is what the atheist has typically said about the universe; that the universe is uncreated and eternal in its existence. No atheist was asking “Who created the universe”? They thought the universe was “Just there,” that it was a brute fact. Although that conclusion is now invalidated by powerful scientific evidence and philosophical arguments. 

Objection - There is no problem whatsoever traversing an infinite chain of events. Every event on that chain can logically be reached. The only thing you cannot do with an infinite chain of events is reach the beginning or the end because those don't exist. Every event is logically reachable. The only way you could not reach your destination on an infinite chain is if you set your destination to the end, but that's because by definition there is no end and no beginning. Every other destination is not only possible but guaranteed.

Reply This makes no sense.

Let's say that the Big Bang is 0 and our present time is 14.  Yes, we can count from -99 to 0 and then to 14.  But first you have to get to -99, and then you have to get to -100, then you have to get to -101, then you have to get to -102, ad infinitum. It's absurd to think because we can count to 100 that the problem of the infinite regress has been solved.