Axiological and ethical justification (as described in the description) require axiological and ethical "oughts".
1. The is-ought gap.
The
is-ought gap is the idea that there doesn't appear to be a justifiable method to justify "oughts" (statements about what axiologically or morally ought to be) using only "is" statements (statements that are merely descriptive.)
An "ought" is often regarded as a type of "is" statement, a statement describing something that just so happens to be moral/axiological. However using the common definitions under the context of the is-ought gap, "is" statements are exclusively statements that do not describe anything ethical/axiological, and "oughts" are statements that do describe something ethical/axiological.
My main point: In order for Con to demonstrate that we probably ought (not) to do something using only common "is" axioms, they will need to demonstrate that this gap can at least probably be bridged.
2. Occam's Razor.
Occam's Razor is the problem-solving principle that recommends searching for explanations constructed with the smallest possible set of elements.
In other words, we should assume that simpler hypotheses are more likely until we have sufficient evidence to justify more specific hypotheses.
My main point: Our default should be to hold that there are no oughts, since that hypothesis requires less elements to justify.
3. Argument against free will.
Given that Con implied (in the comments) that they will take a Christian angle to this debate, I will provide an argument against it.
Much of Christian theology seems dependent on the existence of free will (defined as that which is sufficient to justify moral responsibility), and generally christians are metaphysical libertarians, so at first I will attempt to refute the relevant forms of libertarian free will.
P1. If the probability of an event is 0% or 100%, it is entirely determined to occur or not occur.
P2. If the probability of an event is between 0% and 100%, we can break the probability down into a deterministic part and a random part. (By saying that it's entirely determined to have the particular probability that it does, and that it's entirely random what the actual outcome will be within that probability.)
P3. Given premises 1 and 2, every event must be entirely made up of random and/or deterministic part(s).
P4. No one can have control over anything without in some way having some causal influence over it.
P5. It is impossible to have causal influence over anything entirely random. (If you have causal influence over it, it must be partially determined by you. Something partially determined cannot be entirely random.)
P6. Given premises 4 and 5, for any given event's random part(s) (if it has any), we cannot have control over them.
P7. For anything that can fairly be called a human choice, the human must consciously decide it.
P8. All human conscious decisions are largely caused by underlying mental processes.
P9. Given premise 3, All events in human mental processes must be entirely made up of random and/or deterministic components.
P10. Given premise 6, humans cannot have control over the random components of the events in their mental processes.
P11. Given premises 7-10, whatever ultimate control a human has over a choice must be from their control over the deterministic components of the events in their mental processes that contributed to that choice.
P12. Given premises 7 and 8, more than a small group of irreducible mental processes would have to be used for a human to control what the deterministic components of a small group of irreducible mental processes would do. (So multiple choices would have to be used to control a portion of what contributed to a given choice, requiring an infinite regress.)
P13. It is very unlikely that we have an infinite past of somehow controlling infinite choices. (Because it is such a specific and unsupported hypothesis.)
Conclusion. Given premises 11-13, it is very likely that every human's choices are all entirely caused by things ultimately outside of their control.
I can relate, no worries.
Crap I procrastinated too long.
I'm fine with that, I am an agnostic atheist (as in below 50% but above 0% confident in the existence of God, probably specifically somewhere around 1-5% confident).
If I entered this debate, it would end up being a debate about the existence of God, unless you're also a Christian.