[Aiwendil]

If morality exists outside of human invention, then its source is unknowable, and therefore unprovable.

I don't think this is quite right. The implication is that if something exists outside of human invention then it is not epistemically accessible. But the laws of physics are surely knowable, even confirmable, and they exist outside of human invention (or are you a constructivist?).

Logic and science have no answers to the question, “Why?”

Only because the question "Why?" is so often imprecise. Logic and science have a great many answers to specific questions of the form "Why x, given y?" True, they don't answer meaningless questions or ill-formulated questions, but I can certainly live with that.

You may deride or dismiss motives or truths which do not proceed from anything other than pure logic, but I suggest to you that logic alone is not enough.

I will grant that logic alone is not enough. There are several troublesome problems in the foundations of rationality with the result (among others) that logic alone cannot tell us anything about the world. But we can be as strictly rational as possible in admitting further evidence. In other words, one cannot support an assumption simply by pointing out that logic is not sufficient to tell us about the world.

Would you say that you try to live a more or less moral lifestyle?

Yes.

Why or why not?

For two reasons. First, because I still suspect that there may be some purely rational derivation for morality. If there is, then it's good that I am being moral. If there isn't, it doesn't matter anyway.

Second, because it pleases me to be moral. But I do not claim this as a general truth for all people.

I am not arguing that moral actions are measured by the feelings of pleasure or pain that performing them evokes in the moment, nor am I arguing that Kant (or Plato) suggests anything of the kind. Moral actions frequently are difficult, even painful to perform because they involve some personal sacrifice. I’m speaking more of a deep inner happiness, an abiding fulfillment and deep contentment.

This is as I understood you. And again, I think that this fulfillment either reduces to a state of mind or to a set of requirements so strict that the equivelance of happiness and morality becomes tautological.

But perhaps a further clarification ought to be made. Do you claim that the morality or immorality of an action (or intention) arises in direct relation to this fulfillment? Or do you claim that morality simply is what it is, and that it just so happens that happiness is correlated with morality?

As I understand it, Plato and Aristotle claim the former. That is, they think that happiness and morality are, on the most basic level, tied to one another. In their view, it doesn't make sense to talk about morality without also talking about happiness.

In the latter view (which is how I think you are reading Kant), morality can be defined without reference to the happiness or fulfillment of the moral agent. But once it is so defined, a correlation can be drawn between happiness and morality. I'm not sure whether this is Kant's view or not - I had assumed it was not, but your reading is interesting.

I think that the latter view is probably approximately true. That is, I think there may be exceptions. The trouble with the former view is that it does not allow exceptions, for in that view it is meaningless to speak of a "happy immoral person".

Suppose there were a person who, through some neurological abnormality, found it really deeply satisfying to murder innocent people and was deeply troubled by the thought of committing an act of kindness.

Would you say that this person is moral? This is what I think the Platonic/Aristotelian view forces one to say. Would you say that the person is immoral and an exception to the general rule about morality corresponding to happiness? This is what I would say. Or would you say that you don't need to answer because this scenario is impossible? But why should it be impossible? Surely given sufficiently advanced neuroscience such a being could be constructed.