Duty - Kant

I'll just say up front that I didn't particularly care for 'Fundamental Principles of the Metaphysic of Morals'.  Kant writes in a very technical manner, and that's ok.  You have to pay attention and it helped me to take notes so that I could refer back to his definitions.  You have to take it slow and be brave.
What turned me off was the enormous wrong turn that Kant takes almost right out of the gate.

For in order that an action should be morally good, it is not enough that it conform to the moral law, but it must also be done for the sake of the law, otherwise that conformity is only very contingent and uncertain; since a principle which is not moral, although it may now and then produce actions conformable to the law, will also often produce actions which contradict it.

Got that?  We can't trust moral principles unless they're codified in the law.  Something in the act of writing down and creating the law makes it certain.  He doubles down on this later.

Nothing can possibly be conceived in the world, or even out of it, which can be called good, without qualification, except a good will.

Ok.  I can quibble with this, but I'm certainly not opposed to a good will.

A good will is good not because of what it performs or effects, not by its aptness for the attainment of some proposed end, but simply by virtue of the volition; that is, it is good in itself, and considered by itself to be esteemed much higher than all that can be brought about by it in favor of any inclination, nay even of the sum total of all inclinations.

So if you set out to do good, you're doing good, regardless of performance or effects?  This is the opposite of the saying that 'the road to hell is paved with good intentions', right?  I don't think I'm reading that wrong.  A bit later on he discusses those 'who without any other motive of vanity or self-interest, they find a pleasure in spreading joy around them and can take delight in the satisfaction of others so far as it is their own work'.  We may praise and encourage these people but not esteem them.

For the maxim lacks moral import, namely, that such actions be done from duty, not from inclination.

If they had to help others by law, it would be moral.  But doing so for the pleasure that it brings, while praiseworthy, is not moral.
That seems utterly wrong to me.