It would depend. Some ancient Aristotelian would say that since sin is ignorance, you cannot really choose to not pursue it. Even when you're sinning, you are pursuing the good. — Agustino

Alright, that's an answer. But then, as I already anticipated, whence free will?

This is a tautology because of the relationship between happiness, telos, and good. Good and happiness are defined as a function of one's telos. So invoking happiness is nothing but a sophism since it doesn't add anything else - it's just another category which says the same thing as what was already said before. — Agustino

So you're equating goodness with happiness. Again, this seems to ignore part of what I'm concerned about. Ought implies can, so if you say that one ought to pursue one's telos, then it's possible for one not to. If you say that one ought to pursue one's telos because one has to anyway, then the word "ought" is meaningless. If you say that one ought to pursue one's telos because doing so is good, one can ask: why do that? This is to ask why it is in my interest to be good. The answer I proposed was that it is in one's interest to be good because being good will make one happy, and we all desire happiness. Now that you have equated goodness with happiness, you simply beg the question all over again.

But then, as I already anticipated, whence free will? — Thorongil

It's only the later Christians who introduced the radical conception of freedom which doesn't disagree with the Greek conception that sin is ignorance, but adds that the will can willfully blind the intellect and maintain a state of ignorance, even when knowledge is offered and available. — Agustino

Free will is always involved because there are multiple desires within the soul, and if they are not kept in their right hierarchy, and say, the desire for sex is allowed to dominate other desires, then some of those desires will be frustrated. The goal is to bring one's soul in harmony with itself, and this requires an exercise of one's freedom of will.

Note that I am also a determinist, but determinism isn't incompatible with free will. Determinism isn't fatalism.

Ought implies can, so if you say that one ought to pursue one's telos, then it's possible for one not to. — Thorongil

Yes, out of ignorance (whether willful ignorance or not).

If you say that one ought to pursue one's telos because doing so is good, one can ask: why do that? — Thorongil

Yes, but you can always ask why do what is good? Why do what makes you happy? And so on so forth - there's no end to that line of questioning.

Yes, but you can always ask why do what is good? Why do what makes you happy? And so on so forth - there's no end to that line of questioning. — Agustino

Not if you recall the premise I added, which is that everyone desires happiness. To me, free will requires that we need not desire the good. From a Christian perspective, we might say that Adam was deceived and so led into ignorance of the good by Satan. But who deceived Satan? No one. Satan deliberately turned away from desiring the good (which is God), with full knowledge. And yet he still desired happiness, believing he could obtain it by himself. So here's the difference between us:

Agustino: we all desire the good, but can be ignorant about what it is.
Me: we all desire happiness, but can be ignorant about what it is.

Your position means that there is no reason to pursue one's telos. All you can say is that we have one. My proposed solution would be that one ought to pursue one's telos because it makes one happy. The question "why do what makes you happy?" is subverted by the premise that we cannot but desire happiness.

The question "why do what makes you happy?" is subverted by the premise that we cannot but desire happiness. — Thorongil

Just like we cannot but pursue our telos according to me. I don't see how your theory is superior in anyway - in fact, it would be inferior, because you need further suppositions. The Good - not happiness - is First Cause to me - it is that for the sake of which everything, and everyone, acts - even Satan. I am reminded of the story from Tolkien that Iluvatar told Melkor that he is free to sing his own tune, but the whole creation will - despite his own efforts - only get greater and more beautiful - that is the power of turning evil to the good - the greater good in fact.

Just like we cannot but pursue our telos according to me. — Agustino

I disagree. I think it can be deliberately denied with full knowledge.

I disagree. I think it can be deliberately denied with full knowledge. — Thorongil

I would say that this denial requires the willful blinding of oneself to the truth. You cannot both know the truth clearly with full-knowledge and yet rebel. To rebel, you must repress a part of yourself, which is exactly why evil is self-destructive.

For example, you say Satan has full knowledge. Does he have full knowledge that he can never become God? Because it was precisely the desire to become God that drove him to rebellion. So is it possible to desire an impossibility with full knowledge? :s

I would say that this denial requires the willful blinding of oneself to the truth. You cannot both know the truth clearly with full-knowledge and yet rebel. To rebel, you must repress a part of yourself, which is exactly why evil is self-destructive. — Agustino

According to this, it would be impossible for any being to commit mortal sin, which requires not only willing evil, but doing so with full knowledge.

With Satan there's a chain of deception that stops with him. I am compromised in my ability to choose the good due to Adam. Adam was compromised in his ability to choose the good due to Satan. But Satan wasn't comprised by anyone. There is no ur-Satan that deceived Satan. So he must have known fully what he was doing and the consequences of his action, but still chose to rebel anyway. God has to allow a being he creates to do this if he allows him free will.

There is no ur-Satan that deceived Satan. — Thorongil

Wait, why can't Satan deceive himself? :s He has free will afterall.

Wait, why can't Satan deceive himself? :s — Agustino

He can. I'm saying he must have done so with full knowledge.

Yes, and I'm saying he must have done so with full knowledge. — Thorongil

Right, but it is first self-deception that is willed (can we say with full knowledge? clearly full knowledge ends once self-deception is willed), and only THEN does sin and rebellion enter into play.

Right, but it is first self-deception that is willed (can we say with full knowledge? clearly full knowledge ends once self-deception is willed), and only THEN does sin and rebellion enter into play. — Agustino

He possessed knowledge of the good and what would happen if he freely choose not to will it anymore. No longer willing the good is the act of will in this case, which then results in his being deceived. But he knew he would be thus deceived prior to said act of will.

He possessed knowledge of the good and what would happen if he freely choose not to will it anymore. No longer willing the good is the act of will in this case, which then results in his being deceived. — Thorongil

I'm not sure how this would work. You seem to postulate that self-deception comes after sin, but I think that's the other way around. Adam and Eve were first deceived, and THEN they sinned.

Alternatively, from the mortal sin angle, no, he never deceived himself. He always knew and knows what the good is and why he should will it. God wouldn't damn a being who is deceived. So if Satan is damned, then he isn't deceived about the good.

God wouldn't damn a being who is deceived. — Thorongil

Then why are Adam and Eve damned? They were deceived afterall.

They aren't.

They aren't. — Thorongil

The man said, “The woman whom You gave to be with me, she gave me from the tree, and I ate.” 13Then the LORD God said to the woman, “What is this you have done?” And the woman said, “The serpent deceived me, and I ate.”

14The LORD God said to the serpent,
“Because you have done this,
Cursed are you more than all cattle,
And more than every beast of the field;
On your belly you will go,
And dust you will eat
All the days of your life;

15And I will put enmity
Between you and the woman,
And between your seed and her seed;
He shall bruise you on the head,
And you shall bruise him on the heel.”

16To the woman He said,
“I will greatly multiply
Your pain in childbirth,
In pain you will bring forth children;
Yet your desire will be for your husband,
And he will rule over you.”

17Then to Adam He said, “Because you have listened to the voice of your wife, and have eaten from the tree about which I commanded you, saying, ‘You shall not eat from it’;
Cursed is the ground because of you;
In toil you will eat of it
All the days of your life.

18“Both thorns and thistles it shall grow for you;
And you will eat the plants of the field;

19By the sweat of your face
You will eat bread,
Till you return to the ground,
Because from it you were taken;
For you are dust,
And to dust you shall return.” — Genesis 3

I don't see any damnation there. By "damning," I mean, "being sent to hell." And by "hell," I mean, "eternal separation from God." Adam and Eve are clearly not damned.

See here, too: https://en.wikipedia.org/wiki/Harrowing_of_Hell