The conclusion does not follow because you must specify that external factors such as environment and laws of nature, as you do in an earlier premise, also contribute to a lack of moral responsibility. — ToothyMaw
But the conclusion does follow from those premises. So I am just wondering which premise you are disputing. Here is the argument:
A) If we have come into existence, then we have been caused to come into existence by events external to ourselves
B) If we have been caused by external events, then we are not morally responsible for our initial character
C) Therefore, if we have come into existence, we are not morally responsible for our initial character
That argument above is deductively valid. And presumably you would accept that it is sound (though in case you do not, I will say something about A and B's plausibility below).
D) we are not morally responsible for our environment or for the laws of nature
E) if everything we do is a product of matters for which we are not morally responsible, then we are not morally responsible for anything we do
F) If we have come into existence, then everything we do is a product of initial character, environment and laws of nature, none of which we are in any way morally responsible for
G)Therefore, if we have come into existence, we are not morally responsible for anything we do
This part of the argument is also deductively valid. And it is presumably one of these premises - more specifically, E or F, that you wish to dispute. But I am not yet entirely clear which one.
Let's just go through each one in turn, starting with A. Can you reasonably deny A? I do not think so, for denying A would mean having to maintain that one can create oneself. But that involves a contradiction: to create yourself you would have to exist prior to your own existence. So, A is not open to reasonable doubt.
What about B? Well, if you deny B then I find it hard to conceive of on what basis you think determinism is incompatible with free will. You could not, for instance, say that determinism is incompatible with free will because it deprives us of alternative possibilities of a sort only indeterminism can provide. For clearly denying B would mean you accept that it is possible for someone to be morally responsible for something for which they exercised no control at all, namely their initial character. The compatibilist could simply reply to you that as you're happy enough with people being morally responsible for their initial character despite lacking all control over its acquisition, then you should be happy enough with people being morally responsible for what that character subsequently determines them to do.
So, I don't think you can deny B without making your incompatibilism ad hoc.
C follows as a matter of logic.
What about D? Well, clearly you accept this, as you keep appealing to it (and it is self-evidently true). And indeed, the basis for thinking D is true is really the same basis for thinking that B is true, namely that one was not involved in any way in these matters.
What about E? E says " if everything we do is a product of matters for which we are not morally responsible, then we are not morally responsible for anything we do".
Well, from your comments it seems to me that this is the premise that you wish to deny. For I suppose one could argue that it begs the question against the incompatibilist, as an incompatibilist thinks that if some of what we do is the indeterministic product of matters for which we are in no way morally responsible, then we can - somehow - be morally responsible for that product.
But this is not really question begging as the burden of proof is squarely on the incompatibilist to support that claim. That is, E is not default false, but default true. It is prima facie plausible. By contrast, the claim that somehow the involvement of indeterministic causation could transform us from devoid of moral responsiblity for our decisions to morally responsible for them is prima facie implausible. I provided an argument in support of that: I am (by hypothesis) in no way morally responsible for my desire for a pie. And I am (by hypothesis) in no way morally responsible for my desire not to eat a pie. It is - thanks to laws of nature for which I am also in no way morally responsible - indeterministic which of these desires will cause my decision. Well, how does that make 'me' morally responsible for the decision? That seems like magic. It's not like the decision is any more 'mine' than it would be if it had been determined by whatever desire caused it. And it's not like any more control was exercised over it.
The point can be made another way. Imagine that it was indeterministic that I had the initial character that I did. Well, how would that make me morally responsible for that initial character? How would the fact - if it is a fact - that I genuinely could have had a different character from the one I actually possessed, transform me from not being morally responsible for it to being morally responsible for it? The mind boggles. It is surely about as self-evident as anything that whether or not my initial character was one that was deterministically conferred or indeterministically conferred makes not a tiny bit of difference to my moral responsibility for it.
Well, how would things be any different when it is indeterministic which decisions my initial character causes me to make? Again, it seems clear that this is pure alchemy.
So E is not question begging in any worrying way. For we cannot reject arguments or premises that lead to the negation of our position on the grounds that they beg the question, for that is to have rendered one's own view as the touchstone of credibility, when the correct way to proceed is not to have a view, but simply to see what follows from plausible premises.
To reject E, then, one would need a good independent evidence that indeterministic causation alone can magically make one morally responsible for what it produces. I am sceptical such an argument exists.
What about F? F says "If we have come into existence, then everything we do is a product of initial character, environment and laws of nature, none of which we are in any way morally responsible for"
Well, the previous leg of the argument has established that we are not morally responsible for our initial character. And it is obvious that we are not morally responsible for our environment or the laws of nature. So how can you deny F? Even if you are an incompatibilist, you can't deny F, for you don't think we're morally responsible for indeterminism being true, do you? Whether indeterminism is true or not would be a function of the laws of nature - for which we're not morally responsible. (If you think we are somehow morally responsible for hte laws of nature, why can't a compatibilist say the same?).
So, F doesn't beg the question against the incompatibilist, for no incompatibilist is going to deny it. The incompatibilist doesn't claim that we 'are' morally responsible for any of those elements. Rather they just think that if indeterminism (for which we're not morally responsible) is involved in what the combination of those elements causes, then the results are results for which we can be morally responsible.
As such, then, it seems to me that E is the only premise that you can realistically challenge, but you haven't really challenged it yet as to do that you'd need to make an argument for E's falsity, not simply note that its truth - or apparent truth - is incompatible with incompatibilism.