oh no

Also looking back at one dialogue that always stuck out to me between Arthur and Hosea in early game, when referring to John, Arthur says "Running off on that kid is one thing, but theres a code, and he knows that." Now I'm not saying that Arthur thinks it was OK for John to run off on Jack, but he does to some extent believes it is excusable, which makes sense given the crowd he's grown up around, and he's probably just a product of that situation HOWEVER it does have a huge affect on my outlook on how he would be a parent.

If he believes that running off on Jack was excusable its most likely a reflection of his behavior when it came to Isaac, he didn't run off on Isaac, but he only gave that poor kid as much attention as he could without upsetting Dutch for not being around as much, which brings me to another point – Dutch would not appreciate Arthur making any changes in his life to accommodate Isaac and Eliza, we've already seen how he can be possessive and controlling when it comes to what certain gang members are doing. Dutch might even see them as something getting in the way of the gang making more money. I love Dutch as a character but its not crazy to think that in his eyes Isaac and Eliza would be detrimental to the path he sees fit for Arthur, who is essentially 'the work horse'

Another post I saw a while ago (I forget the creators name but shout out to that guy) mentioned that Arthur only put in the amount of effort he could while maintaining his lifestyle, saying "She knew what I was, what my life was" Showing that Arthur believed he did not have the capacity to change his lifestyle so he simply didn't, even though it would have greatly helped Isaac and Eliza.

At most Arthur would probably pity Isaac for having such a shit dad without actually making any changes to improve how he treats him, he probably has a lot of regret about how he treated Isaac and Eliza, as he is necessarily vague in the few scenes Isaac is even mentioned or implied to be mentioned. I believe that Arthur is only so hard on John about Jack when the subject is brought up, is because of Isaac, and not wanting John to make the same mistake he did.

Arthur did teach Isaac how to swim, that is canon, or at least implied when he tells Jack "Y'know I taught another boy to fish once." So I do think Arthur acted partially as a father when it came to teaching Isaac some basic skills a dad is supposed to, like fishing, or MAYBE how to ride a horse. People often use Jack as an example of how Arthur would be a good dad but I really think that doesn't apply, Arthur treats Jack the way he does because of how he regrets treating Isaac IE; this journal entry in chapter 6

"Jack is an innocent little boy, in him I see what I missed."

Arthur has the potential to be a good father, but the only way he could ever be a good father is if the child was intentional, or the child happened POST chapter 6 in a world where Arthur survives. I don't think Arthur would make the same mistakes he made with Isaac again, but he would probably have a whole new set of issues to deal with if he ever had another kid. If i'm being honest, I don't think Arthur even has the mental capacity to deal with being a father again after what happened with Isaac and Eliza,,