What is character, and what role does it play in the decision making of an agent, according to proponents of libertarian free will?

Question

I understand libertarian free will as an agent's ability to choose otherwise, or having more than one course of action available to them, when making a choice at time t, given a fixed past up to t. However, after having partaken in multiple discussions related to the concept of free will on the Christianity site (for the curious, see here, here, here, here), I've noticed that the concept of character is very important for at least some proponents of libertarian freedom. To illustrate this, let me quote this answer:

The "missing link" here is character. God has free will, and is fully capable of being tempted and enticed to do evil, but consistently chooses to use that free will in benevolent and righteous ways.

Or this answer:

Christians have free-will, but their purpose in life is to develop perfect characters that always freely choose not to sin. They can develop this God-like character, but by definition no one can be created with it.

Yet, I still have to understand what character is in the first place. Is there a rigorous definition of character? Does character exist as a "thing" in the first place (i.e., what is the ontological status of character)? Does character have any measurable or detectable causal effects on reality? For example, does an agent's character influence said agent in a way that determines or narrows the range of options available to them at time t, and if so, how?

And what is the relationship between an agent's character and the laws of physics? Is character nothing but an emergent property of the laws of physics, in the sense that the concept of character is a convenient high-level abstraction, but ultimately adds nothing new to what the laws of physics can already explain? Is a person's character nothing but the current state of the neural wiring of their brain? Is character nothing but brain chemistry? Or is character something beyond the laws of physics, not reducible to them, and different from free will at the same time?

And if character goes beyond the laws of physics, where is the information of this character stored? Can it change/be updated over time? Does it obey its own "character update rules"?

In short, what is character, and what role does it play in the decision making of an agent, according to proponents of libertarian free will?

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_{Regarding my sub-question about the relationship between character and the laws of physics, this question is closely related: How do defenders of libertarian freewill reconcile it with constraints imposed by the laws of physics?}

Answer 1

"Empirical Approaches to Moral Character" is a good overview of what you are asking about (c.f. the more general such article), though see also §4 of a different SEP entry for empiricist skepticism about character as such. The SEP article on virtue ethics starts with the remark that:

A virtue is an excellent trait of character. It is a disposition, well entrenched in its possessor—something that, as we say, goes all the way down, unlike a habit such as being a tea-drinker—to notice, expect, value, feel, desire, choose, act, and react in certain characteristic ways. To possess a virtue is to be a certain sort of person with a certain complex mindset. A significant aspect of this mindset is the wholehearted acceptance of a distinctive range of considerations as reasons for action.

Some religious analysts frame such issues in cognitive (or "noetic") terms, so we find an intersection with virtue epistemology:

Virtue responsibilists (e.g., Battaly, Code, Hookway, Montmarquet, and Zagzebski) understand intellectual virtues to include cultivated character traits such as conscientiousness and open-mindedness; call these ‘trait-virtues’. Their approach is broadly aligned with internalist sympathies in epistemology and deeply concerned with cognition’s ethical dimensions and implications.

Akrasia (weakness of will) connects up with any or all of the above topics:

The phrase “all things considered” is not, as it might seem, merely a minor difference in wording that allows weakness of will to get off on a technicality. Rather, that phrase marks an important contrast in logical form to which we would need to attend in any case in order properly to understand the structure of practical reasoning. For that phrase indicates a judgment that is conditional or relational rather than all-out or unconditional in form; and that difference is crucial.

I.e., one might think of moral development as improving one's cognitive standing, of moving (by the gathering of moral "evidence" or the specification of moral reasoning) from all-things-considered to all-out judgments; and this improvement might be construed as character-theoretic (our virtuous traits are built up as strongly as possible when we pass the relevant all-out thresholds).

Is this all something that happens in a "physical" way? Immanuel Kant claimed that the active part of the mind plays into moral cognition and reverses the order of empirical cognition: rather than proceed from apprehension to understanding to reason, we proceed from reason to understanding to apprehension (that last stage here is "respect" as a feeling "wrought by reason"). Such an account is not meant to be absolutely counterphysical, albeit it is not said to be comprehensible on finite scientific grounds, either. If a resolution to the question of character as formed by libertarian willpower were to be embedded in a physicalist theory, this resolution would mean that a physicalist description of libertarian willpower itself had been compellingly realized (something we have yet to achieve as an academic community).

Answer 2

Character is simply the agent's personality, his preferences and values. The agent chooses to do things that serve his preferences, values, needs and long term plans.

These are psychological properties that have nothing to do with physics. There is no conflict between free will and physics.

Morality is how the agent's character aligns with the values of his community.