If the environment is a text, water is one of those who write it. By acknowledging, refusing or ignoring such a statement, either consciously or not, different societies maintain their views about the position of human beings and the role of non-human beings and other entities in the world. This point is relevant to the case of the Kasena people of the chiefdom of Paga, in the Upper East Region of Ghana 
? This article is based on the fieldwork that I carried...,where the local word for rainwater (doa) is taboo for the chief’s lineage members. This article aims at providing the ethnographic scenario and the conceptual tools for understanding such a taboo. It will be argued that the taboo of rainwater is related to the idea, inscribed in local practices and discourses, according to which human beings cannot claim a leading role in shaping the world.
The opposition between beliefs as the main subject in folkloristic studies and the common trend in applied anthropology that focuses on instrumental aspects of culture can be overcome in the context of the anthropology of life, in which no distinction is drawn between material and symbolic aspects of culture in order to construct a comprehension of life processes as co-built by humans and non-humans. As a consequence, water as a symbol of life and water as a resource for life might be reconciled in a processual frame.
That « water is fundamental » is nothing more than a truism. As such, it is not worth noticing if expressed in verbal form in one of the uncountable local variations on the same quasi?universal theme. On the contrary, if the same content is not merely exhibited like a slogan, but rather embedded in social practices, it becomes far more interesting for anthropologists. In this article, water is seen as « fundamental » insofar as its active role in shaping the world is acknowledged. Seeing water as a subject rather than as an object or a resource available to human management opens the way to reframing the relationships between society and environment, on the one hand, and to rethinking the very concepts of society and environment, on the other hand. If water is one of the subjects that « make the world », and if many of these subjects are non-humans, then (human) society does not have an exclusive role as « constructor » and « manager » of the world, whereas the environment clearly emerges as a collective entity, a society whose shape is not moulded by any external factor, but by itself in a neverending process of autopoiesis. In other words, society and environment are closer than expected, or maybe they collapse into one another, as some of the attributes of the former are extended to the latter, and vice versa. The environment is a society, and as such it is also a self?writing text.
In this ethnography of the Kasena, water reveals itself to be « fundamental » in shaping the sacred landscape, both in its « anthropogenic » portions and in its « natural » areas, a distinction that is rooted in the dichotomy « society vs environment », which is parallel to « culture vs nature ». As the generative grammar of the sacred coincides with the generative grammar of the landscape, the relationship between human society and its gods is strictly connected to the experience of inhabiting the world and it can be understood in the terms of the Ingoldian « dwelling perspective » (Ingold, 2000: 5). In the process through which the world is made and remade, water plays its role along with humans and other non-human subjects that we would otherwise label natural entities and atmospheric agents. By physically building or moulding sacred places, water also contributes to the « human » cultural operation through which the meaning of such places is constructed. The understanding of water as a subject challenges the premises of the very modernity from which anthropology has emerged and against which it eventually turned its intellectual weapons. If water is acknowledged as a subject writing the landscape and its meaning, then two fundamental distinctions, the one between nature and culture and the one between natural and artificial, lose their relevance.
Thunders, clouds, pots. And water
« Anywhere there is water, there is a god ». This statement, made by a member of the paramount chief’s lineage, summarizes the problem of identification of the ta?wana buga, the water gods, in the Kasena chiefdom of Paga, in the Upper East Region of Ghana. The wider category of ta?wana includes gods located at ? or rather consisting in – sacred portions of landscape, the Earth shrines 
? The theme of the earth shrines or land shrines,..., a part of which, the ta?wana buga, consists in ponds (buga: lake or pond).
The sacralization of the landscape poses a question about the relationship between environment and society or culture. In general terms, the Paga case shows how a unilateral determinism based on the choice between « the environment determines culture » and « culture determines the environment » is untenable. The case of the Kasena, in fact, sheds light on a monist worldview, in which heterogeneous factors, namely human and non-human subjects, shape the whole that unifies the two modern abstractions called environment and society. Above this level, which is continuously manipulated, there is a principle which is autonomous, which cannot be handled, and whose distinctive status is sanctioned by a taboo: the rain.
The Kasena ritual system produces practices and discourses related to water in which the latter emerges as a constructor of the environment. Whereas a huge number of marginal acts, made by a Latourian assembly of humans and non?humans (Latour, 1999), take part daily in shaping the landscape or, in other words, in mediating between water and soil by constraining the flow of the former, the status of rain is different. Rain, as such, cannot be manipulated. It imposes itself as a higher principle whose paradoxical responsibility is assigned to the highest human authority, the chief, who, nevertheless is not allowed to pronounce its name.
The paramount chief, p?, is in charge for controlling the rain. He exerts his ritual role by providing offerings to the kunkunu kambia (« pot of the clouds »), a pot containing water in which a power related to rain resides. Ritual activities on the kunkunu kambia start between the end of April and the beginning of May, when the rainy season and the agricultural work are supposed to begin. The kambia, through diviners, asks for offerings in order to let the rain be sufficient and not excessive. Then offerings must be repeated later on, as a thanksgiving. The chief calls the elders of the other villages of his chiefdom to inform them that he is about to offer an animal to the kambia and that he wants to share its meat with them. Besides the animal, the chief and the elders would provide chickens, eggs, kola nuts, millet and any other item requested by the kambia. It is the p?kakwia, the « chief’s elder wife », who is in charge for preparing the food. When everything is ready, the chief comes out of his compound to join the elders, who wait for him at the entrance, close to the naabari, the ancestors’ shrine. After immolating the animal, the chief and the elders eat the meat and leave a part of it at the shrine, for the ancestors.
According to the rigid interpretation of the chullu (the normative system of the Kasena of Paga), the chief and the inhabitants of its village, Kaku?, cannot pronounce the word doa (rain). The elders of Babile, another village of the same chiefdom, half an hour by foot from the chief’s compound, own another kunkunu kambia. Whereas the Kakunia (people from Kaku?) avoid the word « doa » and then use the concept of « kunkunu » (clouds), the Babilnia (people from Babile) can mention « doa » but to mean « thunder », instead of using the appropriate term, which is « dubaga ». If the former avoid the significant of « rain », the latter avoid the signified of « doa ». Both the Kakunia and the Babilnia, yet, indirectly approach the rain by evoking a related concept: the clouds, in the first case, the thunder, in the second one.
In order to comprehend the taboo of rain, it is necessary to observe the widest ethnographic scenario of Paga, with specific reference to water, the centrality of which can be showed by focusing on three topics: myth of foundation, housing pattern and sacred places.
The ambivalence of water
The Upper East Region of the Republic of Ghana is part of the North Mamprusi geographic region, North of the Gambaga scarp. It is a granitic plain, the altitude of which varies between 180 and 300 meters. Its lateritic soil is mostly used for cultivating legumes, cereals and vegetables, as is poor in nutrients if compared to the area located South of Gambaga, where yam can be cultivated with success. The Kasena are about three hundred thousand people speaking Kasem and living in Northeastern Ghana and Southern Burkina Faso. Their land, the Kasso?o, was cut in two parts during the Scramble for Africa, more precisely in 1898, when France and the UK traced the border between the present-day Burkina Faso and Ghana at the 11th parallel of northern hemisphere (Duperray, 1984: 2). Today, like the Nankana and the Sissala, the Kasena are still divided between the francophones of the North and the anglophones of the South. As the historians of Africa Giampaolo Calchi Novati and Pierluigi Valsecchi have underlined (Calchi Novati & Valsecchi, 2005: 152), whilst the Kasena and their neighbours lacked centralized institutions and had a weak and diffused form of authority, they were yet able to coexist with their more powerful neighbours, the centralized states of the Voltaic region. The Kasso?o is divided in several territories, each of which is an autonomous chiefdom ruled by its own paramount chief, the p?.In the history of this people, the absence of a centralized authority was crucial in defining the relationships with the nearby kingdoms. For centuries the latter have been profiting by the weakness of the periphery constituted by the Kasena and the other non?centralized societies, using their territory as a reservoir of slaves and a buffer zone (Goody, 1967: 183).
According to the oral tradition, Paga, which rises precisely at the border between Ghana and Burkina Faso, was founded at the end of 17th century by Naveh, a hunter from Kampala (Burkina Faso). Today it is ruled by a paramount chief who is assumed to be the founder’s patrilineal descendant. The territory of Paga, inhabited by less than 2000 people, is currently divided in 24 nawuura (sing.: nawuuri), each of which defines both a parcel of land and a genealogical branch of people living in it. A nawuuri, which is commonly translated in English as « section » or « village », can be defined as a group of compounds whose inhabitants jointly sacrifice animals to their ancestors’ shrine (Howell, 1997: 76).
The most important aspect of Paga’s cultural tradition is the special relationship between local people and their sacred crocodiles, which are described as friendly and harmless. Such a relationship recalls the centrality of water and, more precisely, its ambivalence: the animal is friendly insofar as it is an ally to humans, yet it may attack humans in order to punish their immoral behaviour.
Thechief has recently endorsed a written version of the myth of foundation 
? For more examples of Kasena myths of foundation..., which was formerly circulating in multiple versions due to oral transmission. The story starts from a case of lineage fission. A man called Panlogo, defeated in the competition for the role of chief, takes flight from his father’s house, accompanied by his supporters and chased by his enemies, who want to kill him. During his travel, Panlogo runs up against a river, which appears to be an insurmountable obstacle. The fugitive, then, sees a crocodile approaching him. The man and the animal recognize one another as they remember a pact of friendship between their ancestors. They also renew the deal by swearing again: Panlogo’s descendants will neither eat crocodile meat nor harm any crocodile; each infraction of the taboo will cause death. In return, Panlogo gets an immediate help and a permanent friendship. As the crocodile enters the river, it opens a passage through the waters. Panlogo and his supporters, then, can go across the river. The waters, then, close again before Panlogo’s enemies arrive. The fugitive is now safe and founds the town of Kampala, in Burkina Faso.
Later on, a hunter from Kampala called Naveh (a descendant of Panlogo) falls into a hole and remains trapped there until a crocodile, another deus ex machina, helps him to find a way out before he dies of thirst. The crocodile leads Naveh to a pond, where the hunter can finally get water to drink. After renewing the oath, as his ancestor Panlogo had already done, Naveh decides to settle in the surroundings and give life to a new community: Paga.
Both the episodes, the one at the river and the one at the pond, tell us that the crocodile is a valuable ally, as it can guide and support human beings in relation to the crucial ambivalence of water, source of life and mortal trap at the same time. During Panlogo’s escape, water is described as an obstacle and consequently a threat, whereas in the second episode Naveh needs water. In the first episode the crocodile saves the man from water, whereas in the second one the former helps the latter by means of water. Furthermore, whilst water, in the first episode, can be a threat only in connection with a group of human beings chasing Panlogo, in the second one it is precisely the absence of human settlements to make it difficult for Naveh to get water to drink. In other words, water is neither scarse and precious nor abundant and dangerous as such, as a « natural entity », but always in an interactive social context which makes it either an opportunity or a constraint for humans. Water is ambivalent and fully embedded in social relations.
Water and residence
Water plays a key role in the cultural ecology of Kasena’s housing pattern, as it exerts influence on both the location and the shape of compounds. The traditional Kasena housing unit, the so?o (pl.: sam), is circular, even though more recently built compounds are quadrangular, and is surrounded by the lineage fields, the kaduga. The so?o’sperimeter is defined by the single rooms (di; sing.: diga), each of which is inhabited by a nuclear family. The internal space of the so?o includes the naboo, the pen where cattle are kept, and the kunkolo, the courtyard where most of everyday activities are carried out. Outside, the mancho?o is a place for meetings and conversations, mostly for men.
The sam, the Kasena « mud fortresses » (Frobenius, 1912?13: 302), embody and express the human and non-human threats that contributed to shape them in the long term. The so?o’s pattern was elaborated for defensive purposes (Echenberg, 1971): on the one hand, it is to be understood with reference to the danger represented by other human groups; on the other hand, it is an adaptive response to environmental pressures related to water. With regard to the first point, the architecture of the compound and the shape of its rooms are related to the enduring threat to the Kasena society represented by the slave raids up to the end of the 19th century. Local people practised a tactic of survival, as slave raiders were attempting to appropriate both labour and reproductive force. It is in this frame that the configuration of traditional compounds is to be understood, with its symbolization of gender, body and fertility (Fiedermutz?Laun, 2005). The distinction between the compound’s outer and inner sides, in fact, is parallel to the distinction between masculine and feminine, as men tend to spend their idle time in the mancho?o and women tend to stay in the kunkolo, a trend that is marked during funeral rites.
Besides human threats, the architecture of so?o takes into account both opportunities and constraints related to non?humans. In spite of their need of water, settlements must be located far away from rivers in order to avoid the simulium midge, which is the vector of the Oncocherca volvulus, causing oncocherciasis or river blindness. Furthermore, the risk of floods during the rainy season, like the one that occurred in 2007, makes depressions of land not reliable as areas for building houses, as, in addition, humidity is dangerous for both native cereals and cattle.
As a consequence, water emerges as an ambivalent factor, which underlies both life and death and with which humans establish a relationship of attraction/repulsion. Water is necessary for both human beings and their cattle, but its proximity is dangerous. Ideal locations for compounds, then, are parcel of lands characterized by roughness, where the sam are not continuously touched and hence eroded by the flow of rainwater. In fact, the surface, the morphology of soil, that « skin of the land » after which the ta?wana are named, is what makes the « habits of water » foreseeable (Mangiameli, 2013). Rainwater also influences the spatial direction of the compound: only a short segment is left open, the entrance, which faces west, whereas the rooms jointly constitute a wall facing east, standing out against the prevailing direction of wind bringing rain, which blows from east to west.
The so?o’s pattern seems to tell us that in order to inhabit the world it is necessary to know the habits of water and the habits of non-humans towards water as well. In a society in which descent and kinship are understood and described through spatial metaphors based on places such as the house, the room and the Earth shrines (the so?o, the diga and the ta?wana), to ensure the future of one’s lineage coincides with preserving and reproducing those very places in which the lineage takes shape. Furthermore, in case of sacrifice, whoever the beneficiary is, the Kasena always commence by mentioning ba?a W? de o kaane Katiga (« God-the sky – and his wife-the earth). This way, they establish a parallel between any socio-natural event and a cosmic order which is understood as a combination of the masculine and the feminine. In this context, rainwater is masculine as it comes from the sky. If the segmentation of domestic space expresses the order of relationships between the masculine and the feminine in a dialectics of openness and closure which is functional to preserving fertility, the so?o’s direction towards west protects the settlement from rain. The latter, as a source of life, a disruptive environmental factor and a potentially overflowing masculine principle, is then held back.
When a god is thirsty
The ta?wana, les dieux du territoire (Liberski-Bagnoud, op. cit.), literally meaning « the skin of the land », are gods immanent to sacred places consisting in single trees, groves and ponds, and working as junctions of a cybernetic system through which environmental conditions are made intelligible (Rappaport, 1971). Herein I am interested in the latter only, the Kasena sacred ponds, the ta?wana buga. Besides communications via divination, the ta?wana « talk » with humans through their very material conditions, taken as indications of the wellbeing of a wider ecosystem.
Reading the environment is extremely complex, as it implies taking an overwhelming number of factors into account. The role of cultures, with regard to this, consists in reducing complexity, in « taming » it by making a few traits pertinent – in this case, the ta?wana – which have to be kept under control in order to get answers from them. « Keeping under control », yet, might mean not only « observing with attention » but also « manipulating » pertinent traits of the ecosystem in order to receive reassuring answers. The relationship between humans and ta?wana, and more precisely the human intervention which aims at modifying the skin of the land, can be interpreted in an apotropaic frame.
A ta?wam buga may sometimes be « thirsty », as it is commonly said in Paga, when its bed is dry. Under such circumstance, it is the pond itself which expresses its thirst via divination seances, as it usually happens with regard to requests of sacrifices. When a ta?wam is thirsty, namely when a pond is dry, it asks for humans to dig in order to make water spring again. When it is time to dig at Katogo, the pond where the « crocodiles of the chief’s palace » dwell, it is the chief himself who supervises the work. On the basis of what divination has stated, some nawuura and not others are called for cooperation. By all means, the nawuura that are considered members of the same descent and « younger » than the chief’s nawuuri are the most likely to be involved.
Two points need to be stressed: first, as it has been said, it is the ta?wam itself that makes a request; secondly, the environmental conditions for this request to be made are likely to occur every year, during the dry season. Nevertheless, as the elders of Kaku?, the chief’s nawuuri, have underlined, the digging is rarely put into action. Its execution in Kaku? was requested only twice in the last seventy years. More precisely, the last two chiefs, Awampaga Tedam, in charge from 1938 to 1970, and Awia Awampaga, who succeeded his father and is still in charge, have ordered the works once each. The latter did it in 1976 at the already mentioned ta?wam buga of Katogo, whereas the nawuuri of Nania soon followed Kaku? by executing the same operation at its own sacred ponds, Chura and Chobuga.
Resorts to this instrument are limited: a chief can make recourse to digging ponds not more than three times in his life, and as we have just seen the last chiefs did it once each. Such a limit raises a question about the extent to which quenching the pond’s thirst is an act of worship or rather a way to pursue the political and ritual interests of the leader. If Katogo, the pond where the chief’s lineage crocodiles live, acts as a device for monitoring the state of worldly things, what it poses under surveillance is precisely the chieftaincy itself, as the welfare of Katogo’s crocodiles coincides with the welfare of chief’s lineage. By digging at Katogo, the p? puts to use a number of important stratagems. First of all, he shows how willing to meet the ta?wam’s needs he is, which is crucial as the Kasena ritual constitution provides for cooperation between the chieftaincy and the cult of the ta?wana. In the second place, he does it in a location, Katogo, which represents the fusion of the two principles, chieftaincy and ta?wana, as it is a ta?wam hosting the crocodiles of his own lineage. In the third place, by asking the other nawuura for cooperation, he tests his own authority: if, on the one hand, he shows his loyalty to Katogo, on the other hand the other nawuura will show their loyalty to him. In other words, by quenching the sacred pond’s thirst, the chief reconfirms the ritual-political shape of Kasena chieftaincy.
The last two times in which Katogo was renewed, under the chiefs Awampaga and Awia, occurred during the early period of power of a new chief. Both the chiefs rectified the dynamics they were able to read in their environment, and more precisely, in the morphology of Katogo, in order to start their chieftaincy and to dispel the fear of an ecological, demographic, political and ritual decay. It is for this reason that the chief is not allowed to endlessly repeat the same operation: such an apotropaic act cannot be reiterated to infinity because that could be interpreted as a way for the authority to stack the deck. If it is necessary to allow non?humans to communicate what they want, namely their will, a state of crisis, an emergency, or rather a temporary or ultimate interruption of their cooperation with humans, then the latter are not allowed to modify the « statements » of the former at their own pleasure. In a context in which gods might die, contextually highlighting a worrisome circumstance, repeatedly digging sacred ponds would sound like a heroic treatment, self?defeating for humans.
Since the will of the gods takes the shape of, and is acknowledged a posteriori as, the unpredictable outcome of the non?linear dynamics of the complex adaptive system in which humans live, the apotropaic digging cannot be endlessly repeated. In fact, this would imply that the complex system had to shelter an extraneous body, the conscious purpose (Bateson, 1972), which is exactly what has no room in complexity.
The same limit of three interventions in a leader’s lifetime, however, concerns the puru shrine of the chief’s compound. This shrine consists in a heap made of domestic daily waste. Its size expresses and results from the expansion of the lineage, whereas its shape also depends on the action of atmospheric agents, the main of which is certainly rain.
As the puru is subject to landslide, the chief can periodically request for his people to work on it in order to restore its vertical shape. The logic of this operation is parallel to the one ruling the digging at the ponds. In fact, it rectifies the structural collapse of the heap in order to reassert the vitality of chief’s compound. Precisely as it happens in the case of sacred ponds, the leader is not allowed to resort to repairing the puru more than three times in his life. As stacking the deck in order to inscribe a conscious purpose in the environment is not allowed, then the operation cannot be endlessly repeated up to the point of ignoring the non-humans’ answer by systematically removing the effects of their actions and their fallout on the prestige of ritual leaders.
Water as author
Several local practices and discourses about the ta?wana reproduce the assumption that the ensemble of non-humans ? namely what we would call « nature », in a modern view – is not simply available to society as a passive object to be managed by human subjects. An example comes from the artificial sacred pond of P?dambuga (literally, « the powerful pond of the chief »), whose dam was built by the British during the colonial rule, in the early 50s, in the context of a wider project that aimed at increasing water availability in Northern Ghana.
P?dambuga receives the flow of water in excess coming from another sacred pond, which, in turn, is artificial. As a consequence, the latter was to be considered – in local terms – « P?dambuga’s father ». The difference in altitude and the temporal anteriority of the first pond were translated in the idiom of descent. The flow of water from the older pond to younger one determined a kind of positive contamination, a transmission of power: a basin receiving water from a ta?wam could not but become a ta?wam itself, a younger one, lower in a hierarchy. The flow of water, then, established both the connections between the places and their position in a hierarchy. Water writes the map of sacred places in the landscape.
The active role of water raises a question about the creation of P?dambuga: who is the creator – or the author – of the sacred place? In local terms, it is the sacred place itself as a god (ta?wam). In other words, the author is the environment, as the local attribution of a sort of « authoriality » to ta?wana refers to the ensemble of interacting entities in which each ta?wam consists, namely the ecosystem. This matter is crucial in order to frame the local understanding of the relationships between humans and non-humans, and then to comprehend the taboo of rainwater. Otherwise, the answer might well have taken the relationship between a project and its execution into account, as the pond was planned by a colonial power and built by local labour, whereas in other cases it was the Kasena themselves that decided to act. Is the pond inauthentic as it was made by the British? In fact, the distinction between external and internal factors pushing for modifications of the landscape could be used to read the evolution of the environment and its meaning. On the one hand, the « internal » could be read as « authentic » and the « external » as « fictitious », as permanent evidence of foreign rule, an evidence that was incorporated by the landscape. On the other hand, the internal and the external could be creatively reinterpreted, through some kind of a mimetic attitude, as pass keys to understand the so?called « contradictions of modernity ». Both choices, yet, would underline and confirm the meaningfulness of the distinction between the Kasena « us » and the British « them » (or vice versa) which is not relevant to the social discourse on ta?wana.
In this context, on the contrary, the line separating « us » and « them » is the one between humans and non?humans, and it is the latter that have the last word, as any modification of the landscape is to be « approved » by the ta?wana, as the locals use to say. The growth of vegetation and the emergence of an ecosystem, with fishes, birds and the inevitable crocodiles coming to dwell in or by the pond, have two basic features: first of all, they constitute a clear answer, an a posteriori confirmation that non-humans « agreed », that they appreciated the modification; secondly, non?humans contribute to the very evolution of the landscape by shaping it along with humans.
On this basis, although the human intervention at P?dambuga was acknowledged, the word « artificial » seems not to be the right attribute of the pond, as the pond is not considered to be a human creation. As I was told, « we have just dug, water was already there ». The active subject in constituting the ta?wam is neither « the British » nor « the local community », but the environment in itself as an ensemble, with a specific major role played by water, whose presence does not depend on humans. The latter can just make an attempt to have a « dialogue » with water, in order to « convince it to stay », on the basis of a fragmented knowledge about its habits in relation to the skin of the land. In spite of everything, then, P?dambuga is not artificial and the role that the British played in its creation has no relevance. P?dambuga, as the other ta?wana, emerged from the intertwining of humans and non?humans.
Let us now examine another example, the twins ta?wana of Chobuga and Bomburi, respectively a pond and an arboreal collective, fifty meters away. The latter hosts a shrine and is the location of sacrifices the contents and purposes of which are referred also to the former, insofar as the pond and the trees are « the same thing ». In the past, Chobuga was a source of drinkable water. It is for this reason that, according to the chullu (the « Kasena tradition »), after the wedding rites, the new couples have to visit the pond, so that the ta?wam can « take into account » the increased water requirements related to the birth of a new family, by making its own water level get higher. As it happens elsewhere, in Chobuga we record a circumstance in which the sacred/natural works as a control device showing the welfare of an entire environment, similarly to the size of the puru, the behaviour of crocodiles and the conditions of the ta?wana buga.
The two ta?wana are distinct but united, twins, as they are considered part of the same system. The flow of rainwater, in fact, runs along Bomburi before getting to Chobuga. The circulation of water between different ta?wana connects them and lays the foundations of their supposed kinship relation and their perceived equivalence: « they are different, but they are also the same thing », as it is commonly said in Paga.
Bomburi's morphology is extremely interesting. It consists in a strip of land of about thirty meters, on which a line of trees grows, slightly higher in altitude than the surrounding area. During the rainy season, Bomburi is encircled on the one side by the water of a rice terrace and on the other one by a small stream flowing towards Chobuga. Bomburi, then, constitutes a kind of tiny ephemeral island which allowed trees to grow on it, and whose very presence and actual shape, conversely, depend on the action of trees. Whilst the latter holds the soil, water erodes all around, deepening the difference between the bed of the stream and the strip of Bomburi, which is « untouched » by water. Day after day, such difference becomes higher and then the profile of the ta?wam gets clearer.
In order to understand the duplicity of water gods it is very useful to take into account an aspect of the notion of analogism proposed by Philippe Descola. According to the French anthropologist, analogism 
? Descola argues that West Africa is one of the regions... is « un mode d'identification qui fractionne l'ensemble des existants en une multiplicité d'essences, de formes et de substances séparées par de faibles écartes, parfois ordonnées dans une échelle graduée, de sorte qu'il devient possible de recomposer le système des contrastes initiaux en un dense réseau d'analogies reliant les propriétés intrinsèques des entités distinguées » (Descola, 2005: 280). In this context, the role of the sacrificial pattern is crucial, insofar as Descola proposes to understand sacrifice as the instrument that was developped « afin d'instituer une continuité opératoire entre des singularités intrinsèquement différentes » (Descola, ibid: 320).
In the case of the « twin » ta?wana, then, a continuité opératoire connects two places in which water is involved in two different relationships with vegetation. Whilst at the sacred pond water is encircled and contained by the trees growing on the perimeter of the ta?wana, at the grove it is the trees that are surrounded by the water. The flow of water is the trait d'union between two different singularities, a specific feature of which is underlined through sacrifice: they are « the same place », « the same thing ». Through the duplicity of ta?wana buga, the Kasena ritual system suggests the idea that human beings need both the categories of places in order to inhabit the world: on the one hand, places inhabited or habitable by crocodiles, those where water is contained; on the other hand, places inhabited or habitable by humans, namely floor areas, surrounded and not covered by water.
Conclusions: the taboo as a metonymic sliding
The case of the Kasena of Paga casts light on how human institutions can be willing to get non-humans involved in the neverending process through which the world is constructed and inhabited. In fact, the taboo of rainwater expresses – and emerges from a local view about the limit of human action and the meaning attributed to it, with specific reference to environmental conditions. In a widespread Western imagery, savannah is fundamentally an environment characterized by drought. Nevertheless, ethnographic experience among the Kasena shows that discourses and practices inscribed in their institutions point at the double threat posed by water: not only its absence but also its excess. Much of the work on the land, simultaneously ritual and concrete, symbolic and material, has to do with the critical relationship between the surface of the land and the circulation of water.
Among the Kasena of Paga, the concept of natural is understood through the concept of sacred, and more precisely through the metaphor of the « skin of the land », ta?wam, which represents the environment as a body, a sacred body. In fact, the ta?wana are described as natural, in the sense of « something that was neither produced nor manipulated by humans ». If we took this metaphor seriously we should conclude that humans imagine to be moving on the surface of the Earth without having any right or possibility to modify the « skin of the land ». Nevertheless, as it was shown, humans do intervene on their sacred places.
Both by preserving and by modifying the skin of the land, working on its furrows, humans aim at holding and containing water in order to prevent it from both disappearing or flooding out. As they embody informations about the habitability of their ecosystem, the Kasena sacred places, and more specifically the ensemble of water gods, constitute a cybernetic system which provides answers about the conditions of the environment in which the Kasena live. The ritual work materially modifying the landscape is a kind of manipulation of those answers. Yet, as it was shown, the Kasena chullu poses a limit to human interventions, precisely because a negative answer cannot be ignored forever by simply transforming it into a positive one.
Then, whilst the « natural » is described as non?anthropogenic, it is located in something, namely, the « skin of the land » which is often manipulated in the collective endeavour of putting it under human control. With regard to doa, the rain, it is definitely the most important factor in life processes and also the one whose behaviour is the most uncertain (Worster, 1993: 123). Totally out of human control, the rain cannot be mentioned by those who are in charge for the impossible task of controlling it. On the contrary, by working on the « skin of the land », human beings try to influence the « habits of water ». The latter is the hidden metaphor underlying the former: the « habits of water » are inexpressible insofar as they represent the powerlessness of human beings up against the environment. In other words, the ta?wana conceptually cover up rainwater. Assumed to be « natural », they attract attention on themselves and simultaneously divert it from what is really « natural », in the sense of non?anthropogenic: rainwater.
To conclude, the taboo of rainwater implies that the members of the chief's lineage have to replace the word « rain » with « clouds », whereas the members of an associated lineage, Babile, use the word « doa » to mean « thunder ». The metonymic sliding underlines that rain cannot be mentioned because it cannot be controlled. Above the surface of the land there is an absolute, non?manipulable level, which is epitomized by rain. The paradoxical responsibility upon this level is assigned to the highest human authority, the paramount chief: without rainwater there would be no chief as there would be no society. If the act of naming things implies a vocation to ruling over them, the taboo of rainwater points at the limit beyond which this power cannot be exerted, and consequently at the limit beyond which no human action can be meaningful, as in fact no human action and no meaning are thinkable. The clouds of the paramount chief express the meaning of limit and the limit of meaning.