Long before volition manifested on this planet, processes were driven by the expediency of the moment into a future that was possible. Then life showed up, but it had no volition. Life was still bound by the availability of the values it needed to perpetuate itself. Temporary localized shortages of such values either led to migration, parasitic behavior or termination of the lineage. Thanks to the agents of chaos within it, life was capable of variegation in the strategies it used for perpetuation through value acquisition. This resulted in more stabler forms of life.
Volition manifested on earth in the form of life called man. Man was different from the life that preceded it because he could produce the values he needed. Shortage of food? No problem! He cultivated plants to do his bidding. Shortage of water? No problem. He drilled wells. But more importantly, what separated him from other life was that he could choose NOT to produce the values he needed in spite of what his faculties of foresight told him. That is, he did not have an instinct or an automatic form of knowledge that forced him to produce. He could disobey the oracle within him.
Digression: This is why all statements about morality suffers from the is-ought “problem” first identified by David Hume. All statements about morality is how man ought to behave, and is never how he behaves or will behave in a given situation. This is not a problem like philosophers would love to think. People who think the is-ought “problem” is a problem are merely unknowingly holding a premise that there is an underlying rule that inexorably guide human behavior. In other words, they believe it is possible to achieve totalitarian control over man’s choices either through prediction or through coercion. But that is impossible. Man will always be able to disobey the oracle within him. This is the nature of volition. End of Digression
So man needs a morality that prescribes how he ought to act (not will act or is acting). It is trivial to derive what this morality would prescribe. It would prescribe choices which, if taken would result in a successful state of life, which I hereby define as happiness – not to be confused with the Nietzscheian hedonistic term with the same spelling.
Certainly theft would be a sin in this morality. A society of parasites cannot and will not exist for long. Once everyone has consumed everyone’s loots in such a society there will be nothing left to loot and everyone would perish. The only form of exchange in this society would be trade. i.e. free voluntary exchange of produced value. But why should you care? You are not the society are you? Why don’t you act in the expediency of the moment and, steal? The truth is, there is nothing that can force you to not steal. All you have is a reason why theft would result in mutual destruction of all parties involved, including you. This knowledge cannot force you to produce and not steal. But it has all the reasons for you to produce and not steal. There is lot more to say on what is sin and what is not sin in this morality. But I will save it for some other time.
Digression: It is interesting to note that this rationally derived form of morality has evolved in biological and social evolution. e.g. Piranhas are atheists but they don’t eat each other. e.g. Small tribes consider individuals valuable for production, and therefore considers murder a sin because it results in lesser production. However since we are capable of volitional reasoning, no longer do we need to rely on these forms of automatic moral knowledge a.k.a moral instinct. It is perfectly possible to derive moral precepts from reason. End of Digression
We have seen why only voluntary exchange of value should be allowed. This might lead to symbiotic parasitism, but this is OK.