Q: WHY ARE THERE ANY NSE BEINGS AT ALL?
The data to explained is this:
D: THERE ARE NSE BEINGS.
There are three possibilities:
i We explain D by
appealing
the existence of some nse beings.
ii There is just no explanation
for fact that there are some nse beings.
iii We explain D by appealing
to the existence of some non-nse being.
i This can be ruled out as viciously circular. We cannot explain why there are any nse beings by appealing to that very fact. That is the very thing we are trying to explain, and it does not appear to be self-explanatory. Every nse being is one which might not have existed. There is no necessity in the existence of any of them. Each one is such that we can easily imagine the universe without it. We can keep iterating this thought experiment until we imagine a universe without any nse beings at all.
ii This is no explanation at all. This is to give up on the task of explaining D. Maybe there is no explanation. Maybe existence is a completely inexplicable mystery. Just a brute fact.
iii This is at least an explanation. Furthermore, unlike i is not circular (because it does not appeal to the existence of the very same sorts of things whose very existence we are trying to explain). So it is an explanation, and it is better than the only other explanation on offer (namely, i).
Problem: Why should we prefer (iii) to (ii)?
An example: Suppose (i) I hear a scream; (ii) I rush outside and stumble on the dead body of somebody who bears obvious signs of recent serious wounds; (iii) Further down the street I see a man running off with a dagger in his hand and blood on his shirt. I immediately jump to the conclusion (iv) that the fugitive killed the man at my feet by stabbing him.
(i), (ii), (iii) do not constitute conclusive evidence for (iv) . In other words, the evidence before me does not constitute a valid argument for the conclusion.
(STOP! Think of a way of showing that it is not a valid argument: that is, think of a possible state of affairs in which (i), (ii), (iii) are true but in which (iv) is false. If you can think of one such possible state then that shows that the premises here do not guarantee the truth of the conclusion.)
Despite the fact that (i), (ii), and (iii) do not entail (iv), it seems I would be rationally justified in believing (iv) given the evidence encapsulated in (i), (ii), and (iii). This is because (iv) is the best explanation around for the evidence in hand. It explains why I heard a scream, why the man before me has a stab wound, why the fugitive has blood on his shirt, why he is disappearing quickly from the scene of the crime. There is no other good explanation of the observable facts in the offing. And so, given this evidence, it seems reasonable to accept (iv). More evidence would be needed to convict the fugitive of murder in a court of law, but even there evidence that is sufficient to convict him will not usually deductively entail (iv). The evidence will be good enough for a conviction if it puts (iv) beyond reasonable doubt (not beyond all possible doubt).
In our philosophical theorizing we will often have some puzzling data which require an explanation. If there is one philosophical theory which explains the data better than the rest, then we have a good reason for preferring that theory. It is not a conclusive reason—at best it constitutes the kind of support for the theory which (i), (ii), (iii) lend to (iv).
In general we accept: