The fact that only humans above a certain age can be morally virtuous, rather than babies or cats, means that that being moral requires some cognitive ability. If virtue is about desires, it is worth remembering that you can't desire some things without being able to conceive of them. Suppose a virtuous person will desire to make people happy and desire to tell the truth. You can't desire to make people happy without having the concept "happy" and you can't desire to be truthful if you don't have have the concept "lie", so a cat or a baby cannot desire these things.

For those of us who want to have control over all our mental states, compatibilist substitutes - such as desiring what we desire to desire - will always be like being told, when you desperately want there to be a God, that yes, God exists, as God is simply the good within people.

I don't think we are all irrational every time we fail to see through an argument in a book, but suppose it's true about you. You are still more rational than you think you are. You are irrational in a minor way - believing a misguided theory of the nature of rationality - but rational in a major way - you respond well to probabilistic evidence as you go through the day.

Sometimes we deliberate - for example when we plan a long trip or - if we are not math wizards - when we solve long division problems. However, if we deliberated every time we acted we would never get through the day. Most of the time, we act for reasons without deliberation. I am not just talking about cases of simple, habitual action, like brushing your teeth, but also about more sophisticated action.

A person is praiseworthy for a right action to the extent that her action manifests, and is rationalized by, good will, that is, concern for the right and the good, not necessarily under the description "right" or "good". A person is blameworthy for a wrong action to the extent that her action manifests, and is rationalized by, ill will - concern for the wrong and bad, also de re - or moral indifference - lack or deficiency of good will.

Though we think intrinsic desires tend to be pretty stable, we do not think they imply anything like the amount of predictability in behavior that traditional virtue ethics requires for someone to have a one-word-in-English character trait such as "benevolence". Other things being equal, a person with more of a desire for other people's wellbeing will do more for other people's wellbeing, but things are almost never equal.

People of relatively low intelligence can be morally wonderful if they desire the right and the good (not necessarily under the description "right" or "good"). Their low intelligence sometimes results in their accidentally doing something wrong, but doing something wrong out of low intelligence alone is like stepping on a person's foot because you are (literally) blind or missing a cry for help because you are (literally) deaf. We do not judge the blind or deaf person as morally bad.