Actually, it is often the case that a person has no clue about what is best for them (think of a child whose idea of best for me is all the ice cream I can eat). If what I think is best for me is getting the promotion over Joe in the next office, and I can do it by underhanded sabotage without getting caught then, on your reasoning, that is what I ought to do.
Indeed. What is “best” or “good” is purely subjective and ultiamtely aesthetic.
Dostoevsky’s Underground Man, in Notes From Underground, explains it more eloquently than I could:
What is advantage? And will you take it upon yourself to define with perfect accuracy in what the advantage of man consists? And what if it so happens that a man’s advantage, SOMETIMES, not only may, but even just, consist in his desiring in certain cases what is harmful to himself and not advantageous. And if so, if there can be such a case, the whole principle falls into dust. What do you think—are there such cases? You laugh; laugh away, gentlemen, but only answer me: have man’s advantages been reckoned up with perfect certainty? Are there not some which not only have not been included but cannot possibly be included under any classification? You see, you gentlemen have, to the best of my knowledge, taken your whole register of human advantages from the averages of statistical figures and politico-economical formulas. Your advantages are prosperity, wealth, freedom, peace—and so on, and so on. So that the man who should, for instance, go openly and knowingly in opposition to all that list would to your thinking, and indeed mine, too, of course, be an obscurantist or an absolute madman: would not he? But, you know, this is what is surprising: why does it so happen that all these statisticians, sages and lovers of humanity, when they reckon up human advantages invariably leave out one? They don’t even take it into their reckoning in the form in which it should be taken, and the whole reckoning depends upon that. It would be no greater matter, they would simply have to take it, this advantage, and add it to the list. But the trouble is, that this strange advantage does not fall under any classification and is not in place in any list . . .
. . . The fact is, gentlemen, it seems there must really exist something that is dearer to almost every man than his greatest advantages, or (not to be illogical) there is a most advantageous advantage (the very one omitted of which we spoke just now) which is more important and more advantageous than all other advantages, for the sake of which a man if necessary is ready to act in opposition to all laws; that is, in opposition to reason, honour, peace, prosperity—in fact, in opposition to all those excellent and useful things if only he can attain that fundamental, most advantageous advantage which is dearer to him than all. “Yes, but it’s advantage all the same,” you will retort. But excuse me, I’ll make the point clear, and it is not a case of playing upon words. What matters is, that this advantage is remarkable from the very fact that it breaks down all our classifications, and continually shatters every system constructed by lovers of mankind for the benefit of mankind. In fact, it upsets everything . . .
. . . Only look about you: blood is being spilt in streams, and in the merriest way, as though it were champagne. Take the whole of the nineteenth century in which Buckle lived. Take Napoleon—the Great and also the present one. Take North America—the eternal union. Take the farce of Schleswig-Holstein .... And what is it that civilisation softens in us? The only gain of civilisation for mankind is the greater capacity for variety of sensations—and absolutely nothing more. And through the development of this many-sidedness man may come to finding enjoyment in bloodshed. In fact, this has already happened to him. Have you noticed that it is the most civilised gentlemen who have been the subtlest slaughterers, to whom the Attilas and Stenka Razins could not hold a candle, and if they are not so conspicuous as the Attilas and Stenka Razins it is simply because they are so often met with, are so ordinary and have become so familiar to us. In any case civilisation has made mankind if not more bloodthirsty, at least more vilely, more loathsomely bloodthirsty. In old days he saw justice in bloodshed and with his conscience at peace exterminated those he thought proper. Now we do think bloodshed abominable and yet we engage in this abomination, and with more energy than ever.
Which is worse? Decide that for yourselves . . .
. . . Then—this is all what you say—new economic relations will be established, all ready-made and worked out with mathematical exactitude, so that every possible question will vanish in the twinkling of an eye, simply because every possible answer to it will be provided. Then the “Palace of Crystal” will be built. Then ... In fact, those will be halcyon days. Of course there is no guaranteeing (this is my comment) that it will not be, for instance, frightfully dull then (for what will one have to do when everything will be calculated and tabulated), but on the other hand everything will be extraordinarily rational. Of course boredom may lead you to anything. It is boredom sets one sticking golden pins into people, but all that would not matter. What is bad (this is my comment again) is that I dare say people will be thankful for the gold pins then. Man is stupid, you know, phenomenally stupid; or rather he is not at all stupid, but he is so ungrateful that you could not find another like him in all creation. I, for instance, would not be in the least surprised if all of a sudden, A PROPOS of nothing, in the midst of general prosperity a gentleman with an ignoble, or rather with a reactionary and ironical, countenance were to arise and, putting his arms akimbo, say to us all: “I say, gentleman, hadn’t we better kick over the whole show and scatter rationalism to the winds, simply to send these logarithms to the devil, and to enable us to live once more at our own sweet foolish will!” That again would not matter, but what is annoying is that he would be sure to find followers—such is the nature of man. And all that for the most foolish reason, which, one would think, was hardly worth mentioning: that is, that man everywhere and at all times, whoever he may be, has preferred to act as he chose and not in the least as his reason and advantage dictated. And one may choose what is contrary to one’s own interests, and sometimes one POSITIVELY OUGHT (that is my idea). One’s own free unfettered choice, one’s own caprice, however wild it may be, one’s own fancy worked up at times to frenzy—is that very “most advantageous advantage” which we have overlooked, which comes under no classification and against which all systems and theories are continually being shattered to atoms. And how do these wiseacres know that man wants a normal, a virtuous choice? What has made them conceive that man must want a rationally advantageous choice? What man wants is simply INDEPENDENT choice, whatever that independence may cost and wherever it may lead. And choice, of course, the devil only knows what choice.
As is often the case, Dotoevsky has the best last word. And decades before Rand even picked up her first pen.