Kant's Groundwork for the Metaphysics of Morals, Chapter 1
It's impossible to think of anything at all in the world, or even beyond it, that could be considered good without limitation except a good will. Anything else is up for abuse. Understanding, wisdom, judgment, courage, resolution, perseverance, whatever such talents of the mind may be called, are undoubtedly good and desirable but they can also be extremely evil and harmful if the will with which they're used isn't good.
History stands as a testament to this. Hitler's perseverance, the Manhattan Project's collective genius, Genghis Khan's leadership; crusades, colonialization, slavery. Any oppression of the greater human project has resulted from somebody's extraordinary capabilities. It's only the presence of a good will that prevents chaos.
For the coolness of a scoundrel makes him not only far more dangerous but also immediately more abominable in our eyes than we would have taken him to be without it. — Kant, Groundwork for the Metaphysics of Morals. Chapter 1
Kant's ideas are largely based on subjective consequentialism, championing the value of intention over that of an act itself. Consequences aren't what make a good will good; it's inherently good. Taking a few minutes out of your day to help the old lady cross the road is a good act. Now, if you get her run over, things get a little blurry. Kant, unlike objective consequentialists, argues that your goodness is founded in your intention of helping the old lady; that neither usefulness nor fruitlessness can change the goodness of your act.
In the natural constitution of an organized being, Kant assumes as a principle that there is no faculty for an end other than what the organism's end is itself. In other words, there is no part of any sensible design that serves a purpose different from the design's ultimate purpose — to include an accelerometer in a laptop is insanity. So, if we must consider that the highest good — the ultimate function of man — is happiness (pretty reasonable), we must also concede that Nature or God or whoever's in charge has seriously screwed up in gifting us with reason. Instinct is beyond enough to achieve pleasure and happiness; to be victims of reason serves no real purpose to our "highest good". Galileo's efforts made him nonetheless happier than the colonial British who rejoiced in India's depredations. Van Gogh was manically depressed, Boltzmann killed himself, Ehrenfest took a bullet to his own head, Woolf was an insomniac, Kafka lived a tormented life, Darwin was unhappy, and Hemingway was riddled with paranoia. It's not often that you find those whose functions align entirely with their happiness. So, why did any of them commit to their own purpose? Answer: to produce that good will you've already heard so much about. We must use our reason to drive our good will.
Now, this does not mean that reason should be the ultimate arbiter of life. Those who have experimented with reason, if only they are candid enough to admit it, fall prey to a certain degree of misology. In allowing reason to govern, you find that it has in fact only brought upon more troubles than it has brought happiness. You then finally envy rather than despise the more common run of people, who are closer to the guidance of mere natural instinct and don't allow reason much influence on their behavior. We must admit then that reason is founded in a far worthier purpose of our existence, to which, therefore, and not to happiness, we destine ourselves.
It is reasonable to believe that Nature has everywhere gone to work purposively in distributing its faculties and capacities and so there must be a function for reason in the human experience; if this function is not that of happiness, which we hold to be the supreme good, the true vocation of reason must be to produce a will that is good, not perhaps as a means to other purposes, but good in itself for which reason is absolutely necessary. That, however, doesn't translate to discarding happiness; it's in the fundamental nature of man to pursue pleasure and pleasure he pursues. That's reasonable too (pun intended). But how exactly does reason help good will? Enter: duty. We all know what duty is. It takes a strong reason to determine one's duty, and a good will to execute it — these are right actions, actions that are ends in themselves, and actions done because we have an obligation to do them. Duty, like morality, lies in some implicit understanding of the mind. We can't quite tell what duty itself is unless confronted with the problem of exercising our duty.
To be benevolent where one can is a duty. But many are so sympathetically attuned that, without any ulterior motive of vanity, they find inner satisfaction in spreading joy around them. Kant asserts that although such an action conforms to duty, it nevertheless has no true moral worth and is on the same footing with other inclinations; the inclination here being that of inner satisfaction.
Suppose, then, that the mind of this philanthropist were overclouded by his own grief, which extinguished all sympathy with the fate of others, and that while he still had the means to benefit others in distress their troubles did not move him because he had enough to do with his own; and suppose that now, when no longer incited to it by any inclination, he nevertheless tears himself out of this deadly insensibility and does the action without any inclination, simply from duty; then the action first has its genuine moral worth. — Kant, Groundwork for the Metaphysics of Moral, p. 12
After all, helping somebody because they offered you a fiver isn't all that great anyway. Kant champions the view that we have an obligation to ignore our inclinations, even if they point us in the right direction. An action is only truly worthy when one does it because they must, because they have a duty to do so, and not because of some greater inclination to honor, fame, or satisfaction. Help people out even if nobody's watching, donate to charity even if the world doesn't hear of it, and be a good man even if it doesn't make you feel good. The only worthy actions are those that come from a place of duty.
That's character, doing the right thing when you don't want to — doing it solely out of the virtue that it's right. We're not commanded to love our enemy. That's insane. You can't command love. But you can command the act of it — we're commanded to act with love, good will, and respect to even the most atrocious people.
For, love as an inclination cannot be commanded, but beneficence from duty — even though no inclination impels us to it and, indeed, natural and unconquerable aversion opposes it — is practical and not pathological love, which lies in the will and not in the propensity of feeling in principles of action and not in melting sympathy; and it alone can be commanded — Kant, Groundwork for the Metaphysics of Morals, p.13
Only actions done from duty have moral worth. I've said that a dozen times now. Simple enough. But more than that, they have worth because we will them from duty, never because of some aim we attain or even intend. As Kant puts it, the worthiness of an action lies in the maxim in accordance with which it is decided upon. So, it doesn't depend on the realization of the object of the action but rather only upon the principle of volition in accordance with which the action is done. Do we have a duty to help little children and caterpillars and old ladies cross the road? Yes, but those actions aren't right because somebody is being helped, they're right because we are rightly motivated. This motivation comes from duty.
Having spoken so much about duty, it's important to consider where it comes from. Kant holds the stand that duty comes from respect for the law. What law, you might be wondering? Roman law? Immigration law? International maritime law? No.
All so-called moral interest consists simply in respect for the law. I ought never to act except in such a way that I could also will that my maxim should become a universal law. — Kant, Groundwork for the Metaphysics of Morals, p.15
That's the law we're talking about. We want to always act in a way such that we wish everyone would act. This doesn't necessarily mean acting in a way that yields the outcome everybody wants (since, clearly, outcomes don't matter). This also doesn't mean acting from those desires we think everybody should or does possess (since, again, inclinations don't matter). Kant means that we must be guided by a principle that supersedes our desires and the outcomes, such that our guiding principle is a universal one, and was it the case tomorrow that a pigeon gained reason, it would know our law as well. If your actions held true for yourself and for others, would the resulting inconvenience still justify your moral transgression? Respect for the law is an estimation of a worth that far outweighs any worth of what is recommended by inclination and that the necessity of action from pure respect for the practical law is what constitutes duty. You can't "never lie except when it's convenient", "keep promises unless they have bad consequences", or "only help people when you feel like it". Any such maxim is to be repudiated because its universality is detrimental.
If lying is wrong, it's wrong for everyone. If theft is wrong, it's wrong for everyone. If killing is wrong, never do it. If something is wrong, it is wrong whatever the consequences. Kant holds that even in situations where benefits to the majority might ensue, wrong things are wrong and you must fall back on virtue because duty calls.
If adversity and hopeless grief have quite taken away the taste for life; if an unfortunate man, strong of soul and more indignant about his fate than despondent or dejected, wishes for death and yet preserves his life without loving it, not from inclination or fear but from duty, then his maxim has moral content. — Kant, Groundwork for the Metaphysics of Morals, Chapter 1, p.11
Now, it's never easy to abstract away from our inclinations and desires. We're instinctively driven to satisfy these. And sure, we have some intuition about what's right and what's wrong but it's easy to say that conflicts between morality and desire result in our transgressions of the law. That's what makes philosophy so important — to restore our sense of duty, to remind us of reason, and to allow us our morality. We're then sorted in the long run. Probably.
As always, thank you for reading!