I’ve always believed that keeping kosher was not just a way of creating Jewish identity, but also a way to create a society attuned to the earth. After years of wondering why some animals are kosher and others are not, I found an ecological explanation for these rules (see section VI). I’m sharing it with the hope of getting some feedback.
I. Why do we keep kosher? I want to open up this question by taking a look back to parshat Noach. Usually when we think of the Noah story, we think about how Noah’s family was given permission to eat animals (read more about this on neohasid.org and on jcarrot. ) But parshat Noach is also the first place where we (that is, all humanity) are given laws restricting how and what we eat.
Even though the laws about keeping kosher, kashrut, may seem like the most specifically Jewish of practices, they have their origins in this “Noachide covenant”, where the first restrictions on eating are described. Those restrictions are to not eat a limb from a living animal and to not eat the blood of an animal. Both are the basis of many kashrut rules.
The Noah story is also the first time the distinction between ‘pure’ and ‘unclean’ animals is mentioned (Noah is told to bring seven of the pure (tahor) animals, which are the ones we call kosher.) So even the least universal aspect of kashrut, the “cloven hoof and cud-chewing mouth” requirement, has its roots in one of the Torah’s most universal stories.
That’s a good jumping off point for searching out the universal meaning of these culturally-specific, arguably parochial laws.
II. Judaism arose in a particular place within a particular ecosystem. While Jews live everywhere, our rituals are keyed to the seasons and rhythms of the land of Israel. This is not just true of Judaism. Each culture evolved in an ecosystem that shaped not only its diet and cuisine, but also its fertility and rain rituals, its pantheons and ways of worship. The reason why there are different cultures is not primarily political or theological, it’s that each society must find a way to teach its generations how to live in harmony with its unique ecosystem.
The most important way this teaching used to happen was through religion, through its rituals, rules and stories. This is an obvious part of Judaism if you think about the relationship between the holidays and the harvests. Kashrut is just as important as the holidays to how Jews express their Judaism. Does this principle apply to kashrut as well? Is kashrut also connected to the earth in the intimate way that the holiday cycles are?
III. Before I go more into ecology, it would help to explore a related dimension of kashrut and eating, taught to us by anthropology. One of the primary ways that a culture expresses its values and its sense of belonging in the world is through eating. (Levi-Strauss’ The Raw and the Cooked was one of the most important works that established this point.)
In fact, one of the primary ways of “civilizing” ourselves is to separate killing from cooking and eating. For a lion must eat and hunt with one and the same mouth. Only a few species (e.g., primates with hands) can even theoretically make a separation between killing and eating. Humans, in fact, are the only predators who have the capacity to completely separate killing (or capturing) from eating. This truth is embodied by the law given to Noah to not eat “a limb from a living animal” (’ever min hachai).
This civilizing process sounds like something that separates people from Nature. Yet by emphasizing humanity’s uniqueness, such rules can also restrain human power and strengthen our empathy with all the other animals.
IV. In Judaism, this drive to elevate our human uniqueness through how we eat is deeply embedded in the powerful rules about how we slaughter animals, the central focus of kashrut. Separating the blood from the flesh is first described in the Noah story, and then in other parts of the Torah, as the way we respect an animal’s soul and life in the face of using it for food: ki hadam hu hanefesh ‘You will not eat the blood because the blood is the soul’.
The imperative to not eat the blood, combined with the imperative to not cause an animal suffering, allows for only one way of kosher slaughtering, what we call shechitah. Shechitah is supposed to accomplish both goals (if done properly) by using an extraordinarily sharp knife to cut the carotid arteries, jugular veins and trachea of an animal in one cut. Done correctly, it’s supposed to allow the blood to flow out and the heart to continue pumping, while rendering the animal unconscious.
Salting meat to draw out any remaining blood, and most importantly not cooking the flesh produced by an animal’s death with the milk that nurtures life (basar v’chalav or milchig and fleishig) are more ways of creating separations between the life of an animal, the death of an animal, and the act of eating. All these rules and rites sanctify the act of incorporating another animal into our own life and body. These laws are uniquely a part of the covenant of the Jewish people, but they are hinted at in the respect for the animal’s life and soul expressed in the Noah story.
Just as rules about how we kill and prepare meat distinguish human beings from other animals, rules about the way people harvest plants, which separate farming from foraging, are also a “civilizing” force found in most cultures. In Judaism, laws about pe’ah (not harvesting the field corners), leket (leaving the gleanings), and kilayim (not interspersing species in a certain kinds of fields), not only underline our humanity; they also add a dimension of holiness and restraint to the act of taking from the earth.
All of these ritual laws, even those that begin in some sense as universal principles, create both a separation between humanity and other species, and between Jewish culture and other cultures. Along with this comes a sense felt by many Jews that Jewish culture is somehow more civilized. That sense of election, so to speak, is a strictly anthropological dimension, without any direct ecological benefit. But the other anthropological meanings discussed above, to the extent that they create a heightened sensitivity to the lives and species that we use and eat, as well as an awareness of death and life itself, are universal in scope and have a clear ecological benefit.
VI. Returning to the main point: every religion arises or is shaped by a place and teaches how to live in that place. Though every ritual has many levels interpretation, e.g. historical, theological and personal, the ecological meaning may be the soil in which all else grows. The depth of this meaning is not in generalities, but in the details.
In the case of kashrut, for example, the rule about not eating blood makes it almost impossible to eat hunted game. In an ecosystem where humans depended on large herds of wild animals like buffalo, as we find in the North American plains, this rule would be almost impossible to follow. But in an ecosystem where wild herds and habitats are less productive, a hunting culture is unsustainable. A culture where humans can carefully control the size of domesticated herds to fit the limits of the ecosystem and the needs of the population is what’s called for. That was the ecosystem which shaped the religion of our ancestors.
This brings us to that most puzzling of categorical rules: which animals we can and cannot eat. Almost everyone knows the rule: mammals that chew their cud and have split hooves are kosher; all other land animals are not. What do these two characteristics of hoof and mouth mean? Anthropologically, there are many interpretations, some of which can be found in Mary Douglas’ Purity and Danger. But ecologically, there is a specific meaning, which goes far beyond any hygienic or other rationalistic or symbolic interpretation.
That meaning practically speaking is straightforward: any animal that chews its cud can eat grasses and plants that are inedible to human beings, and any animal that has split hooves can walk (and graze) on land that is too rocky to farm with a plow. These characteristics together mean one very clear thing: the only land animals that we can eat according to the laws of kashrut are animals that do not compete with human beings for food.
VI. The rules we still follow in Judaism would in their original context in the ancient Mideast have allowed a civilization to thrive, without destroying the ecosystem it depended upon. In an ecosystem which is in some ways marginal, that is, an ecosystem which depends on intensive human input (agriculture and herding), as well as upon intensive “divine” input (i.e., rain, as it was understood by our ancestors), there was no room for devoting good farming land to livestock.
Embedded in this wisdom about locale is another truth: any culture which allows domesticated herds to compete with humans for food also pits farmers against herders. More importantly, it pits the poor who have no land against owners who control both land and herds.
We can easily see the dynamics of this problem in the modern world, where rising world food prices endanger the poor in many countries. Those prices are driven up in part by the industrial practice of feeding grain to cattle, instead of giving them their natural diet of diverse grasses and other pasture plants, and they are also driven up more recently by the use of grain to make ethanol fuel. Instead of competition between herders and farmers, we have competition between feeding our SUV’s and cattle, and feeding other people.
In order to have justice, which may be the most important value within Judaism’s culture, there needs to be a way for farming and animal husbandry to produce enough for all people, poor and rich. The way to achieve this value in different ecosystems might be different, but any culture founded on justice will always find a way to bring this value into alignment with its ecosystem.
Going from animal husbandry back to agricultural rituals, it is obvious how the farmers took care of the poor: enough was always left over for people to glean and harvest, and in every seventh year, when the land was treated as ownerless, everyone (including every animal, wild or domestic) had the right to take from any of the produce of the land. (Some rabbinic interpretations of the law even require fences to be removed to make that easier.) In the fiftieth year, the land was redistributed according to a plan which gave each family an equal share.
With respect to animal herds, the way that wealth was recalibrated was more subtle: the products of the sacrificial system, which combined offerings and tithes of domesticated animals (including all first-born and most other male animals) with plants (first-fruits and tithes of produce and grain), went not only to the priest and Levite, but in many cases also to the poor and disenfranchised. The Priestly class, who had exclusive rights to parts of the sacrifices, weren’t allowed to own land and didn’t need land. But this privileged class received a significant portion of their wealth alongside the lowest class, those who didn’t own and who were entitled by need.
I think this system would have had the potential to eliminate a lot of the stigma associated with receiving charity and to minimize class differences. In combination with all the agricultural rituals and rules mentioned above, we can see the plan for a society that was both socially and ecologically sustainable for many generations.
Ecologically, the sacrificial system also had a very specific lesson: the life and soul of the animal, found in the blood, remained holy, even after the animal was slaughtered, and the only suitable use for this lifeblood was as an offering to God.
The kind of industrial meat-production we see in our time would have been impossible, because it would fly in the face of every ecological, humane, and health consideration that underlies kashrut. The sacrificial system also fits into a broader pattern of rituals and rules related to animals and to the land, a pattern that gives us a unique model for how to create a sustainable civilization.
VII. My hypothesis for why animals must have cloven hoofs and chew their cud is just that: a hypothesis. It fits into a broader understanding of how the Jewish relationship to food is structured by the Torah, with its emphasis on equity and the sanctity of both human life and all life. If this theory could be proven wrong, kashrut would still have its other meanings. But in a time when all of the world’s religions need to help us steer towards sustainability, it is worth so much to know that Judaism, from its earliest time and earliest stories, has an ecological underpinning that we can all listen to and search for.
Looking at the way Jews stereotypically eat and feel about kashrut, I think we may have a little work to do in order to listen better. But we need to hear this call to sustainability, if Judaism is going to be relevant in humanity’s next century. If the eco-psychologists and philosophers and theologians are right, this search is also a way to become more fully human, and, I would say, more deeply Jewish. B’tei’avon!
* An earlier version of this article was published under the title, “The Earth On Your Fork” in the journal of the Coalition for the Advancement of Jewish Education (summer 2008). The painting is “Peter’s Vision of the Animals” by Doug Jaques, based on Acts 10, where all kinds of animals appear on a sheet before Peter and a voice says, “Get up, Peter, kill and eat!” David Seidenberg is the creator of neohasid.org.
 You might say, what about the law forbidding Adam and Chava from eating the fruit of the tree of knowledge? At least according to some interpretations, God wasn’t setting a law but sharing information, just as we might point to a mushroom and say, “Don’t eat it because it could kill you.” More importantly, that instruction applied only to those two people in that one garden; it’s not the basis for any of our dietary restrictions. But the two laws given to Noah are still included among the rules of kashrut.
 Here’s one example of how religious practices are shaped by the ecosystem in which they evolve: Ecologically, the Tibetans lived in a high-altitude ecosystem which did not allow sufficient protein-rich food to be produced through farming alone, so in order to survive they had to eat some meat. Even though Buddhism historically demanded vegetarianism, Tibetan Buddhism found a way to allow its followers (even its priests) to eat meat, creating rituals and rules that would make this to fit into Buddhist practice.
 I don’t explore the meaning of the rules for kosher sea animals here, and I’m not even sure of a good interpretation. However, one possible meaning of the prohibition against eating shellfish may be that we don’t eat animals where it would be hard to separate killing from cooking , e.g. lobsters, or killing from eating, e.g. oysters.
 While the kashrut rules embody a worthy goal, they are not sufficient in an age of industrial meat production, in which even the “right” kind of animal, raised the wrong way, can deplete and destroy ecosystems.