I do not share your faith in the extent of human knowledge. We observe randomness. This randomness does not necessarily imply choice. It may only imply that we do not know the causal factors of certain phenomena.
But even if the universe were deterministic, it wouldn't mean that we don't make moral choices. It would just mean that those moral choices are part of the deterministic chain.
If they are part of a deterministic chain, then they aren't choices. This is silly reasoning.
The slave's theft may have been inevitable, but it's still a consequence of the slave's dishonesty. That doesn't absolve the slave of dishonesty, quite the opposite: the slave's dishonesty was an indispensible part of that causal chain.
It certainly does dissolve the slave of dishonesty. The slave had no choice but to be dishonest, because something in the causal chain before the dishonesty forced him to be.
By beating the slave into more honest behavior, Xeno didn't think he was changing the future. He thought he was implementing the future as it was bound to be. Note that his actions are the same either way.
Pointing out a very simple example where someone's actions are the same regardless of his belief in fatalism does not illustrate that people's actions will necessarily be the same regardless of what they believe. You cannot argue from a single example to a general rule like that. We have no idea what Xeno would have done had he not believed in fatalism.
In fact, if you believe that people's beliefs affect their choices, then there can be no general rule.
All possible deterministic causal factors would be constrained to satisfy Bell's Inequality. It is an experimental fact that some quantum phenomena violate it.
If they are part of a deterministic chain, then they aren't choices.
Sorry, I don't accept your assertion. Choice is the word that has been assigned to what humans do when they follow a course of action. Choice exists by definition, independently of whether those outcomes were predictable.
Furthermore, a point of mathematics: just because something is deterministic, it doesn't mean it's predictable. To be predictable, it has to be computable, and not all deterministic functions are computable.
"The tragedy of life is that every man has his reasons." -- Jean Renoir
It certainly doesn't spare him the consequences of being caught.
You assume that the paradoxes involved in free will vs determinism are somehow more relevant to morality than Zeno's paradoxes are to mechanical engineering.
Wrap your mind around this simple concept: When two apparently contradictory concepts lead to conclusions that are both demonstrably true, the statement of the concept is flawed. The debate over free will remains mental masturbation until it can be couched in terms that can be tested experimentally.
"Randomness" from lack of knowledge of causes and "randomnes" observed in quantum mechanics are not the same.