A Necessary Being?

[Angrboda]

What makes an uncaused first member more possible than an infinite regress?

My initial response to the question was to consider it a schoolboy objection, but on second thought decided that you may actually be curious about why the demonstration of the 3rd Way excludes infinite regress as a viable option.

Keep in mind that proper interpretation of this demonstration only works for an essentially ordered series in which the existence of a thing depends on something essential to its existence. For example, human beings could not exist apart from some material composition. That is part of our essence. The existence of a human being depends, necessarily, on the existence of molecules and atoms that in turn depend on subatomic particles and so on down the line toward more fundamental levels of existence perhaps terminating in the quantum vacuum.  But if there is an infinite regress then it's turtles all the way down below the quantum level. Seems absurd, but let’s just go with it anyway because lots of things appear absurd at the quantum level (at least in traditional modern mechanistic terms). So if we allow infinite regress then the chain of existence extends from human beings all the way down through an infinite series of turtles. Doesn’t that mean that at least one thing inside that infinite chain must exist?

I don't believe you answered the question. What does it matter if one thing inside an infinite chain exists? Say it's quarks or quantum fields, how does that get you any closer to stating a preference between an uncaused cause and an infinite regress? What about a different example, such as assuming the B theory of time, and postulating that the universe is temporally unbounded--there is no first member. This points to a possible flaw in the dichotomy which led you to the preference in the first place, as it is a series that doesn't require a first member. We can give examples, but examples don't answer the general question of why the absurdity of an uncaused cause is more palatable than the absurdity of an infinite regress in the general case.