There are in nature animal parasites who feed on others. Some humans may be so constituted that they do best for themselves when they prey on producers. It’s certainly not universal, because there cannot be a society consisting entirely of parasites; in fact, the parasites must be a relatively small minority; but there can be a society consisting only of producers. But it is “natural.” True, no animal creature routinely preys on its own kind. But perhaps if it could or were smart enough to realize the benefits of such predation, it would. What reason is there, then, to declare parasites unjust aggressors?
The parasite needs the host, but the host would be happy if the parasite just dropped dead. Now on the market there is a certain benevolence or good will between a businessmen and his customers who exchange for mutual benefit. Of course, in giving up my good or money I am motivated by what you are giving me, so the exchange is self-interested on both sides. Yet both of us benefit from each other’s existence in a most visceral and basic sense, whereas the “political” exchange between the parasite and the host who (say) by surrendering his goods avoids the parasite’s violence is not beneficial to the host.
Regarding business competition, it is true that several applicants for the same lucrative job may view each other with hostility. Several mousetrap businessmen competing in the same market have every reason to dislike each other and desire that the competitors make some mistake. They, too, want each other to drop dead. Therefore, either an exchange benefits both parties, or in the case of competition where one wins and the other loses, this competition has been via the cunning of the economists turned to serve the greater good or directed to increase the general happiness.
In other words, Intel would be happy if AMD just up and disappeared and vice versa. However, their competition is in the interest of the whole, whereas the strife between the parasite and host, though their interests are also opposed to each other, does not result in any greater prosperity, in fact it lessens overall prosperity as compared with laissez-faire.
Parasite-host is a permanent relation, and it is unjust from both standpoints. “You disgusting creature,” we are liable to say, “How dare you exist? You suck the lifeforce from your victim, you filth!” Relations should be such that people benefit from each other’s existence and actions. Any Smith should be able to say to any Jones: “I am glad that you exist / were born. Without you, our society would not be as pleasant.” Even with market competition, it proceeds by initial appropriation of unowned goods, production, and mutually beneficial exchange. And of course, it redounds to the greater good.
Cooperation then proceeds by strict libertarian law. No unjust violence is permitted. Competition within the market fulfills the utilitarian strictures and so is also justified. Parasitism, such as tax serfdom or regulationism, ought not to exist.