Within nearly all the great religions of history we find contemplative traditions which espouse the curious principle that foregoing excessive wealth and consumption (and therefore energy use) will actually make one happier. As a general rule these traditions advocate eating only what one needs to be healthy; exercising to maintain physical vigor (but not excessive strength); studying to attune oneself to the subtleties of nature and of the mind; and shielding oneself from the distractions of daily life. All this, they claim, will result in a fuller, more joyful existence.

How is this possible when, evolutionarily speaking, humans are relentless energy-gathering machines. If we didn’t take in more energy than we expend, we couldn’t have survived. In prehistoric societies finely balanced between enough and too little, it made sense to gather as much energy as one could and store it. The calories from gorging on a beast felled in the hunt were stored as fat. (Fat was good in those days!) As techniques for preserving food such as smoking and salting arose, these became ways to store calories outside the body. And, with the advent of agriculture, surplus grain became a very efficient way to store calories needed to make it through the winter.

We are beings attuned to a world of scarcity, or at least, periodic scarcity. Now comes industrial society with its industrialized agriculture that produces so much food that it can now support 7 billion people and perhaps as many domesticated animals. In fact, the amount of food is so great and predictably available that a human population genetically designed for scarcity has become obese by the hundreds of millions in wealthy countries. It is our natural instinct to gorge when extra food is around–in case there isn’t any later on. But, at least in wealthy countries, there always is.

And yet, the contemplative religious traditions live on. Some people point to the best lived examples of those traditions as “the next step in human evolution.” They might mean the Christian saints. Or the Sufis in Islam. Or the Zen monks in Buddhism. But clearly members of these contemplative orders are not “the next step” because such people have been with us for a very long time. In evolution-speak, they have been selected for. My question is, What purpose do they serve in society from an evolutionary point of view?

It seems as if they are almost a separate branch of the human evolutionary tree. Yet, given that many of these traditions foreswear family life, how can they be considered more “fit” than others outside such traditions? And, still they reappear with every generation, as if humankind carries some recessive gene for the contemplative life that shows up again and again.

Some will certainly argue that contemplative religious traditions are strictly cultural phenomena. But every cultural phenomenon is at its base a genetic and therefore evolutionary one. Non-adaptive behaviors disappear after a few generations. Behaviors exhibited by adherents to these traditions must somehow be adaptive.

And, that’s why I ask if we have anything to learn from these traditions about a possible path to sustainability. Certainly, they have much to say about the current frazzled spiritual state of humankind, a state engendered at least in part by excessive energy consumption. Now, don’t get me wrong. I don’t think the great mass of people is going to adopt the disciplined life of the monk. But I see the monk’s life as a sort of model of energy conservation. And, it’s one that celebrates the result of self-restraint rather than lamenting it. Such a path finds that life is made more vibrant through restraint rather than excess.

This path, however, is not necessarily just associated with religious traditions. The materialist philosophers of ancient Greece known as Epicureans demonstrate a non-religious path to a life of self-restraint. Today, we wrongly identify the Epicureans with excess, when this view of life’s aims actually comes from the Cyrenaics who were, to our way of thinking, pure hedonists. They believed that life should be devoted to pleasure derived from sensation. They did not deny that pleasure could come from mental activity. But such activity was secondary.

The Epicureans also believed that maximizing pleasure is the goal of life. But this goal should be pursued through self-restraint in mind and body. Excessive eating only leads to discomfort and disease later. Preoccupation with sexual gratification only leads to disappointment and frustration. Epicureanism–contrary to popular conceptions–was actually a sort of asceticism. But it was not based on devotion to a deity, but rather a frank evaluation of the human condition, particularly its material aspects without reference to religion per se.

Is there is a message in all this for those who will live in an energy-constrained world? Any such message does seem like it would be a hard sell. But, perhaps no selling will be necessary as energy constraints bear down on us and force us into simpler lives. Still, there are ways to live simply and badly, and there are ways to live simply and well. Some make fun of a sustainability movement that tells people that a simpler life is actually better in many ways. Perhaps that message merely reflects cultural traditions that have been with us since the beginning of history. Or perhaps it represents an evolutionary pathway that is ready to reassert itself when the right conditions arise.

Kurt Cobb is the author of the peak-oil-themed thriller, Prelude, and a columnist for the Paris-based science news site Scitizen. His work has also been featured on Energy Bulletin, The Oil Drum, 321energy, Common Dreams, Le Monde Diplomatique, EV World, and many other sites. He maintains a blog called Resource Insights.