Greed is conventionally understood as "intense" or "excessive" desire for wealth in some form. But notice that desires are not themselves any form of force or coercion. It is the actions one takes which may constitute aggression -- whether or not they are based in such a desire.
Suppose someone "intensely" desires, say, my car. They might offer to buy my car, which would be perfectly rights-respecting and therefore perfectly compatible with laissez-faire capitalism. Or they might try to steal it, which would be a violation of my rights, and therefore utterly incompatible with capitalism.
Being the social/economic system that flows from the recognition and defense of individual rights, capitalism needs no check on greed because it does not constitute any threat to others' rights. Any "excessive" desire for wealth on someone's part would only constitute a threat to their own life, as it is the product of a confused heirarchy of values which could lead them to act against their own long-term interests. That is simply not a matter for the law.
(It is a bit of a distraction for the above discussion, but notice that the conventional understanding of greed treats "intense desire" and "excessive desire" as essentially the same in an evaluative sense. That would be a package deal that bundles together fundamentally dissimilar things, and therefore it will encourage various confusions. Someone intensely valuing wealth is not morally troubling at all, and that intensity could easily be a sign of great virtue. On the other hand, someone excessively valuing wealth means that there is necessarily confusion or conflict in his hierarchy of values, which is indeed worthy of a negative evaluation. Yet the evaluative connotations around "greedy" puts both of these in the same normative bucket. That is very dangerous for people who want to think clearly about such matters, which should be all of us.)
answered May 28 '11 at 20:02
Greg Perkins ♦♦