"Alone on his island, Robinson Crusoe can do whatever he pleases. For him, the question concerning rules of orderly human conduct — social cooperation — simply does not arise. This question can only arise once a second person, Friday, arrives on the island. Yet even then, the question remains largely irrelevant so long as no scarcity exists. Suppose the island is the Garden of Eden. All external goods are available in superabundance. They are "free goods," just as the air that we breathe is normally a "free" good. Whatever Crusoe does with these goods, his actions have no repercussions — neither with respect to his own future supply of such goods nor regarding the present or future supply of the same goods for Friday (and vice versa). Hence, it is impossible that a conflict concerning the use of such goods could arise between Crusoe and Friday. A conflict is possible only if goods are scarce; and only then is there a need to formulate rules that make orderly, conflict-free social cooperation possible."
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