(There's a title I've used before, but what the hell)
A [man] finds in himself a talent whose cultivation would make him a useful man for all sorts of purposes. But he sees himself in comfortable circumstances, and he prefers to give himself up to pleasure rather than to bother about increasing and improving his fortunate natural aptitudes. Yet he asks himself further "Does my maxim of neglecting my natural gifts, besides agreeing in itself with my tendency to indulgence, agree also with what is called duty?" He then sees that a system of nature could indeed always subsist under such a universal law, although (like the South Sea Islanders) every man should let his talents rust and should be bent on devoting his life solely to idleness, indulgence, procreation, and, in a word, to enjoyment. Only he cannot possibly will that this should become a universal law of nature or should be implanted in us as such a law by a natural instinct. For as a rational being he necessarily wills that all his powers should be developed, since they serve him, and are given him, for all sorts of possible ends.That's the third of four examples Kant uses to illustrate the application of Categorical Imperative No 2, "The Formula of the Law of Nature", to wit:
Immanuel Kant Groundwork of the Metaphysic of Morals (my literals & glosses)
Act as if the maxim of your action were to become through your will a universal law of nature.
Kant's argument here, roughly nutshelled, is that if every talented person in the world acted like those South Sea Islanders and lounged around drinking and passing around social diseases all day, not a lot of work would get done and a lot of people - except those with natural aptitudes for drinking and innovative fornication - would waste their God-given talents. Personally, I don't share Kant's conviction that this would necessarily be a bad thing. Neither, apparently did the crew of The Bounty, among others.
What sort of talents would it take to make a man useful for all sorts of purposes? We needn't concern ourselves with women. After all Kant didn't - philosophical legend (which I've checked with various members of philosophy faculties over the years) has it that he died a virgin. Apparently his own duty to cultivate his natural talents didn't extend to passing it on to the next generation. That's a little ungenerous - let's give due consideration to the possibility that even in Eighteenth Century Germany "It's your duty to help me perpetuate my philosophical genius into the future" would have been a lousy pick-up line.
Leaving aside Kant's obviously useful, and scrupulously cultivated, talent for philosophy, the field is pretty well wide open. As long as it makes us useful men. For some purpose, or purposes. To whom we have to be useful and how is left pretty open. And look, discriminatory as it might appear, I am going to leave the women out of this because I've go no intention of buying into a big blog-fight by telling women how to make themselves useful.
So let's suppose our hypothetical man discovers that his natural talents are for sycophancy, bullying and manipulation. In modern society, he can find any number of opportunities to make himself useful - to society at large, as a politician, to the shareholders of a corporation as their CEO. And in whatever capacity he employs his talent to make himself useful to others, you can be sure it will be equally useful to himself. If not more so.
Obviously such an individual - sorry, such a man - is duty bound to nurture those talents, even if he has the means to take himself off to the South Seas for a life of more or less carefree carousal with the occasonal interlude of bed rest and antibiotics. And even though the rest of us might wish that a man so blessed with wealth and natural talent would take the South Seas option, the Kantian position is pretty clear. Some people just have to be bastards and that's the way it should be.