It is safe to say that the vast majority of moral rules – explicit or otherwise –concern interpersonal interactions, that is, social behavior. However, it will be advantageous if we can analyze the bare logical structure of moral language and moral behavior without the complexity of social interactions, at least initially. Murray Rothbard recommends the Crusoe thought-experiment for this purpose in his Ethics of Liberty:
One of the most commonly derided constructions of classical economic theory is “Crusoe Economics,” the analysis of an isolated man face-to-face with nature. And yet, this seemingly “unrealistic” model, as I have tried to demonstrate elsewhere, has highly important and even indispensable uses. It serves to isolate man as against nature, thus gaining clarity by abstracting at the beginning from interpersonal relations. Later on, this man/nature analysis can be extended and applied to the “real world.” The bringing in of “Friday” or of one or more other persons, after analysis of strictly Robinsonian isolation, then serves to show how the addition of other persons affects the discussion. These conclusions can then also be applied to the contemporary world. Thus, the abstraction of analyzing a few persons interacting on an island enables a clear perception of the basic truths of interpersonal relations, truths which remain obscure if we insist on looking first at the contemporary world only whole and of a piece.
Murray Rothbard – Ethics of Liberty, ch. 6
So let us imagine Robinson Crusoe stranded alone on a deserted island. He has the width and breadth of the island to himself. There are plants and animals on the island which he may eat in order to survive. There is fresh water to drink. Because there are no other humans on the island, the problem of proper social behavior does not arise. But is there not a question of proper behavior in its most general sense? How should Crusoe act? What should he do? How should he spend his time?
Now, we cannot say that Crusoe ought to do this or that – in the true etymological sense of that word – since there is no one for Crusoe to owe anything to, besides himself. But does Crusoe not owe himself one thing, at least: to not inflict suffering and pain on himself? But we have already broken the terms of the thought-experiment because we are not meddling deities reaching down from Olympus to intervene in the affairs of Crusoe for our own amusement – the only person who can pose the question of what should be done is Crusoe himself: “What should I do?”
Every choice that an individual makes is an attempt to move towards satisfaction and renounce suffering. Hence, we can say that Crusoe’s every action is formally identical with the renunciation of suffering and the attainment of satisfaction. Stated differently, so long as Crusoe is of sound mind, he cannot give any answer to the question “What should I do?” that is inconsistent with the renunciation of suffering and the attainment of satisfaction. Or, to put it in the words of the more ancient – yet perhaps more perspicacious – Epicurus: Crusoe should simply seek pleasure and avoid pain.
The truth of the position that pleasure is the ultimate good will most readily appear from the following illustration. Let us imagine a man living in the continuous enjoyment of numerous and vivid pleasures alike of body and of mind, undisturbed either by the presence or by the prospect of pain: what possible state of existence could we describe as being more excellent or more desirable? … Let him never suffer the pleasures of the past to fade away, but constantly renew their enjoyment in recollection, and his lot will be one which will not admit of further improvement.
Suppose on the other hand a person crushed beneath the heaviest load of mental and of bodily anguish to which humanity is liable. Grant him no hope of ultimate relief in view also give him no pleasure either present or in prospect. Can one describe or imagine a more pitiable state? If then a life full of pain is the thing most to be avoided, it follows that to live in pain is the highest evil; and this position implies that a life of pleasure is the ultimate good.
Pleasure and pain moreover supply the motives of desire and of avoidance, and the springs of conduct generally. This being so, it clearly follows that actions are right and praiseworthy only as being a means to the attainment of a life of pleasure. But that which is not itself a means to anything else, but to which all else is a means, is what the Greeks term the Telos, the highest, ultimate or final Good. It must therefore be admitted that the Chief Good is to live agreeably.
Cicero (quoting the Epicurean Lucius Torquatus) – On Ends, (Section I.XII)
So what is pleasurable, that is, what results in happiness? What eliminates suffering? If he can answer these questions, Crusoe will have answered the question posed at the outset: “What should I do?” He will have established his right ends, which we can refer to – perhaps in an unorthodox manner, in this case – as morality.
What remains is the question of how Crusoe can go about answering these questions. Can he, by reflection alone, deduce what choices will eliminate suffering and bring happiness? Or must he engage in experimental study and observation of his environment and its relation to his own self? These considerations are outside the scope of the present post but I will return to them in a future posting.