Document Type : Research Paper


University of Leicester


What follows is an attempt to see Otto the phenomenologist within wider developments in the field, and to take account of some recent criticisms. Everything that is said falls under the general headingof 'introduction to the study of religion'(or 'meta-religionswissenschaft') Within this wide field, we shall be specifically concerned with the possibility of a systematic phenomenology of religion, and with that phenomenology of religion which takes its starting point from Otto's awareness of the numinous in its non-rational and rational forms and manifestations. In addition to this central insight of Otto's and deriving to a large extent from it, are the morphological categories which can be traced back further than Otto to Chantepie de la Saussaye (1869-1937). These categories form part of classical phenomenology of religion down to Friedrich Heiler (1892-1967). We shall come back to these categories after looking at Otto's numinous as the starting point for a global phenomenology


First, something we must recognise: The concept of the numinous can only with difficulty be considered these days to be the appropriate place to begin a systematic phenomenology of religion. The numinous, it has been objected with increasing frequency, must be consigned to the past. 'Das Heilige' [English title: The Idea of the Holy] appeared in 1917 as Otto was widening his view of religion to take into account recent developments in the expanding field of the history of religions. His research interests were catching up with his travels in North Africa, India, China and Japan. In the first edition of 'Das Heilige' is a popular representation of Durga. Her fearsome aspect represents the numinous. It is all still at the beginning:
not only the study of Hindu deities, but also those features of traditional or ethnic religions, such as homophagy [eating of

FALSAFEH   Vol. 37, No. 3, Autumn 2009, pp. 5-19

human flesh], which fill the observer with shuddering. At first
the numinous, particularly in its non-rational forms, seems to be encountered everywhere where not much is known about the religious forms concerned. The more that is known, so the objection runs, the more the concept of the numinous can be done without. It is something provisional: a kind of interpretive principle for the gaps in knowledge that will inevitably fade away as more accurate information becomes available. Was it not similar with the idea of evolution as applied to the history of religion? It too had slowly to give way before the recognition that every religious system has undergone complex developments down to the present and so cannot fairly be put into some simple evolutionary framework. The reason most commonly given as to why the concept of the numinous should be regarded as dispensable and of temporary value only for the study of religion is that it is basically 'theological' in nature. It was part of a natural theology which was revived by theologians engaged in the study of religion to enable them to look at other religions while continuing to reserve a special place for Christianity. The latter could be considered under the concept of special revelation.a

With regard to the first part of the objection, that the numinous was employed in the early stages in the development of the history of religions and will fade as knowledge increases: we shall have to agree with the critics that the numinous does not really say anything; it does not add anything to the number of facts known about a particular religious tradition. It was Van der Leeuw (1938) who long ago pointed this out. He went on to add that what the numinous does is to safeguard the existential character of the religion that is being turned into an object of study. Van der Leeuw is surely correct here. To retain the numinous is to retain the existential character of religion. We can have amassed a vast array of detail about a particular festival, let us say, but unless we have had in the back of our mind the question of the numinous, and even a personal readiness to sense the numinous, we may not have really grasped the significance of the event for the believers as well as for ourselves. Both Kaufmann (1976) and Sharpe (1983) insist on retaining the existential mode as one basic approach in the study of religion. In the form of the numinous, then we have this
existential mode at the heart of any systematic phenomenology in a way that must prevent the religious facts from becoming objectified and lifeless.

The numinous may, it is true, not need to be linked quite so tightly to some kind of spontaneous religious experience as was the case for Rudolf Otto and, to some extent also Joachim Wach and Friedrich Heiler who followed him in trying to fashion a systematic phenomenology of religion. But even though the numinous is related more implicitly and invisibly to religious forms, it should be in the picture at some stage, if only to remind us that religion itself is in the final analysis shorthand for people being religious.

As for the numinous as part of a natural theology, here we shall have to part company with Van der Leeuw (1938) who accepted it as such. The student of religion should be prepared, I believe, to abandon natural theology altogether, and to choose either the way of 'Religionswissenschaft' [study of religions] or the way of theology, but not seek to combine both. Even Karl Barth (1938) was prepared to praise those 'Religionswissenschaftler' [ones who study religion] who rejected any mixing of religion and theology. He himself did the same, though he took the opposite road of the uncompromising theologian. The numinous, however, may be retained, I believe, without taking on board a natural theology. It is not theology, it says nothing about ultimate reality in terms of the nature or character of the ultimate. What the numinous does do is to safeguard the absolute character of the religion concerned. No religious system may be put down, or arranged with others on some kind of scale, whether higher or lower. This is the message that comes through loud and clear in 'Das Heilige' whatever the evolutionary overtones that accompany it.

Even though we have defended the legitimacy of using the numinous in the study of religion, we would not be prepared to go further and put the numinous forward as the simple principle of overall unity. We would not, for instance, say that Christianity and Buddhism can be subsumed under one essence of religion, the numinous, which may be discerned behind all the forms of these religions. All we are claiming is that the numinous helps us to work towards the unification of the field of religion in terms of some kind of systematic phenomenology.

We may even perhaps go a step further. The numinous may be seen as providing the beginnings of the morphological categories in terms of the distinction between the non-rational and the rational. It matters little whether we conceive of these categories as provisional groupings of material or as rooted in some ontology, as Eliade believed (Brennemann, 1982). What is of interest is their closeness to Otto's central phenomenological insights. Otto himself draws attention to one of the basic categories, sacred space, in relation to Islam and associates Islamic sacred space with the numinous. The sacred word is likewise linked with the numinous in North African Judaism. Sacred time emerges in Otto's encounters with Near-Eastern Sufi dancers and the Orthodox liturgy. The sacred object appears in its numinous character when he reaches India. Sacred action, sacred silence and primordial forms of sacred sound - groans, sighs and the 'Urlaute' [primordial sound] (Otto, 1917, 61ff.; 1932, 203ff.), all may be considered as welling up from the non-rational. They are prior to the rational, just as words, myths, concepts, doctrines, as well as ethical norms are associated with the rational. All this Otto makes clear. In more recent days, Brennemann's chapter on ritual has given us an excellent account of sacred action as grounded in the non-rational and rational expressions of the numinous. Ritual is clarified as that kind of action which thematizes the world (Brennemann, 1982, chap.6). As such its roots must be seen as buried in the non-rational.Nevertheless, that genial work 'Das Heilige' is not to be tortured into some kind of systematic phenomenology of religion. It provides only the beginnings of such. But very fruitful beginnings they were, such that Eliade for instance could elaborate upon them with his wide-ranging ontology using a vast array of material from the traditional religions and from India. Moreover these beginnings of Otto's could also be elaborated utilising the existing tradition of morphological categories going back to Chantepie. In the final analysis, however, 'Das Heilige' must be seen as a work of theology as well as one of phenomenology. Especially towards the end of the work (1917:185). Husserl was right when he felt that ' Herrn Otto...den Phanomenologen Otto auf seinen Schwingen davongetragen (hat)' [Otto the theologian carried Otto the phenomenologist heavenward in his wings] (Schutte, 1969:141). Otto was, after all, a professor of theology as well as of the history of religion.

Joachim Wach (1898-1955), the second of our three phenomenologists, was somewhat freer from the concern with theology than Otto, especially in his earlier period in Germany. Like Otto, however, he was rather preoccupied with the philosophy of religion. Wach believed that to understand religion in all its forms it was necessary to separate the study of religion from both theology and also philosophy. He insisted on the full independence of the study of religion from all other disciplines, including those that provide it with much of its materials. It is the study of religion, he declares, which alone can be properly concerned with the nature of religion. Theology will be looking at the truth of religion. As the basis and object of study, 'Religionswissenschaft' should retain Otto's sense of the numinous, especially when seen in terms of spontaneous religious experience. There is a strong measure of affinity between both men at this point. Thus, in studying a religion such as Islam, one has to distinguish between inner intention in terms of religious experience, and the outer reality on the plane of history (Wach, 1927). Wach proceeded, in his seminal work on laying the foundations for a theoretical science of religion, 'Religionswissenschaft: Prolegomena zu ihrer wissenschaftstheoretischen Grundlegung' (1924), to see the history of the different religions as separate according to their origins and development. However, such development is continually related to the 'sensus numinous' (Flasche, 1978:184). Across the "vertical" historical studies, Wach sets "horizontal" phenomenological sections. These are reached intuitively and constitute materials of significance to the phenomenologist. They are the fruit of hermeneutical or interpretive phenomenology. The horizontal sections, cut through the vertical, historical materials, provide in turn the base for the formal categories or structures to which we have already referred. Although abstracted from the historically and phenomenologically-based materials, these categories have a claim to be empirically based. Such was the bold outline for the systematic phenomenology of religion Wach called systematic 'Religionswissenschaft'.

However, world events interrupted his progress towards realising this programme. In 1935 Joachim Wach, earlier kept out of the chair in 'Religionswissenschaft' at Leipzig, now found himself deprived of his associate professorship, in both cases on account of his Jewish background. He found asylum at Brown university and later at Chicago. He continued to teach history of religions at both these centres. But he was profoundly affected by the destruction of the world he had left behind him at the hands of the National Socialists. He continued at Brown university to defend the independence of his field of study, but the horrendous events in Europe were driving him to make his peace with theology. He became a member of the American Episcopal church; and subsequently, at Chicago, was concerned to stress that the goal of 'Religionswissenschaft' was to be found in a theology of religions with a definitely Christian orientation.

Wach had been helped with his studies in Munich after the first world war by Friedrich Heiler (1892-1967), a Bavarian Catholic now converted to Lutheranism through the 'Religionswissenschaftler', Archbishop Soderblom of Uppsala. Wach's work on the systematic study of religion was thus to some extent shaped by Heiler's own lively interest in the subject. Heiler had not only made a study of Buddhist meditation and written an exhaustive phenomenology of prayer, but in the latter work (Heiler, 1918/1969) had sketched out a systematic phenomenology of religion. It was to remain a sketch for forty years. In 1920 Heiler joined Otto in Marburg where, in fruitful association with the latter, he like Wach adopted Otto's insight into religion as non-rational and rational in its forms and manifestations; he also saw the importance of the numinous as the existential dimension in the study of the subject. Then, with forty years more work in the fields of Eastern and Western religions behind him, Heiler drew it all together in systematic form in a work of 600 pages entitled 'Erscheinungsformen und Wesen der Religion' (Manifestations and Nature of Religion). In this work he utilised Otto's ideas in the sections on sacred space, the sacred community, the concept of salvation, and, above all, ultimate reality ('die Gegenstandswelt der Religion' [the ultimate object of religion]). The last-mentioned he interpreted with Otto as both revealed and hidden. He also took up Wach's programme of a systematic phenomenology of religion and carried it through. He was able to draw on the results of his many studies in the history of religion, his store of folkloric practices and popular religion in Central Europe, and his own large library on the religions that he had built up.

These were the historical sources, to use Joachim Wach's model, from which he derived the significant cross-sections, the material systematic or hermeneutical phenomenology, out of the historical flux of religious happenings. For the formal systematics, the categories, he drew upon the morphological tradition going back to Chantepie de la Saussaye in 1887. Many distinguished phenomenologists contributed to this tradition and refined the initial categories of Chantepie. The period up to 1940, which has been spelt out in detail by Eva Hirschmann (1940) includes E. Lehmann and A. Bertholet (1925) and Van der Leeuw (1933/1938) and Gustav Mensching (1938). Thereafter, phenomenology is taken forward by Mircea Eliade (1949/1958), Geo Widengren (1945-1969), Kurt Goldammer (1960) and W.B. Kristensen (1960). Their categories are utilised by Heiler, further refined, and then systematised in a way that has become widely known, according to the three concentric worlds of religious manifestations, religious concepts and religious experience.The outermost world is that of religious manifestations. Its categories are grouped into three sections. Each category is embedded in the archaic and non-rational. The sacred object - in nature as well as made by hand, sacred space, sacred time and number, and sacred action in all its forms - these make up a first group. Sacred silence, sacred word (from and to the Deity), and sacred writings constitute a second group of categories, likewise rooted in the non-rational as well as the rational, as are also the third grouping of sacred person and sacred community.

Within the world of religious manifestations are two further worlds, each smaller than the one outside it. The world of religious concepts for instance has not only about one fifth of the material assigned to the outer world of manifestations, it also has fewer categories, namely, those of the Deity, creation, revelation, salvation and the last things ('Vollendung im ewigen Leben' [fulfilment in eternal life]). These concepts are roughly grouped into three as in the outermost circle of religious manifestation. The concept of Deity corresponds to the sacred object and the sacred action, that of revelation to sacred word and writings, that of salvation to sacred person and sacred community. The place of creation and the last things seem not altogether clear in terms of the threefold grouping. But what is more clear is that much of what we might call the comparative theology of religions is to be found in the world of religious concepts: theology itself, cosmology, anthropology, hamartiology (sin), Christology and Buddhology and their equivalents in other traditions, soteriology and eschatology. It should also be stressed that the concept of Deity here includes the positive refusal, say by Theravada Buddhism, to allow any concept of Deity at all. Even with this first inner world of religious concepts, the emphasis is descriptive and comparative rather than normative or evaluative: it is history of religions rather than theology.

The second inner circle is the world of religious experience ('die Erlebniswelt der Religion'). If the sacred community brings in sociology, this circle involves studies in psychology. In Heiler's 'Erscheinungsformen' the material here forms again roughly one fifth of that in the world of religious concepts. Again three groups of categories are distinguished out of the eight basic forms and five supra-normal forms of religious experience. The first group comprises awe and fear. These relate to sacred object and action, and to the concept of Deity. Faith and missionary zeal ('Drang zur Mitteilung' [the compulsion to proclaim]) are related to sacred word and writings, and to the concept of salvation. The experience of love is related to sacred person and community and to the concept of salvation. In addition there are the categories of hope and joy, not clearly assigned to a group, along with the five extraordinary dimensions of experience: inspiration, visions and auditions, conversion, ecstasy and supernormal capabilities ('Wirkungen nach aussen' [powers affecting the external world]) such as cardiognosia [knowing someone's heart], transfiguration, levitation, bilocation and the gift of healing. It is to be recognised that religious experience which played so large a part with Otto and Wach here finds a place albeit of smaller dimensions. The overwhelming preponderance of material is assigned now to the more empirical world of manifestations. This, I believe, accords more with the general tenor of recent studies in the history and anthropology of religions. Within the second, inner world of religious experience there is a blank space for ultimate reality, the Deity, the numinous. Turned towards a person it is again threefold: Holiness, Truth and Love. Each of these corresponds to the sub-groups in the circles described earlier. These are attributes of 'deus revelatus', the revealed divinity. However, hidden to a person forever is 'deus absconditus', ultimate reality in a final unknowability.

It is difficult to make clear from such a brief synopsis the fullness of Heiler's 600-page 'Erscheinungsformen ...'. It does have, however, a good claim to be regarded as the best example anywhere of a systematic phenomenology of religion. Both Otto and Wach would have greeted the day of its appearing. It was the culmination of what they were working towards. Not only that, but taken in conjunction with other existing phenomenologies, especially that of Eliade in his 'Patterns of Comparative Religion', and also Van der Leeuw's and Kristensen's as well, the systematic phenomenology of religion has proved to be popular for teaching purposes as well as eminently testable and fruitful in research projects. For instance, Heilerian morphological categories were employed to good effect by J. Marvell in his study of the English place of worship (Marvell, 1985).Nevertheless, the systematic phenomenology of religion has been subjected to some serious criticisms, which should now be examined. Part of the problem was brought about by the classical phenomenologists themselves. They sometimes tended to assume that the systematic phenomenology of religion was more or less the main goal, if not the only goal of the study of religion (Flasche, 1978). But with the recent growth of the study of religion in every direction, this claim became more and more difficult to sustain. For most researchers it came to be simply ignored. The loss suffered then lay in the very fragmentation of the discipline. It began then to lose out in face of more coherent disciplines such as philosophy, history or politics, with the consequences for higher education which are only too plain these days.But there are other, more specific objections as well: The first is that classical phenomenology operates heavily with abstractions, with categories, by which to interpret 'religious facts'. In doing so it tends, so it is argued, to proceed from these categories to the facts which 'illustrate' them, instead of starting with the facts and then building up empirical, 'ad hoc' connections between them. Such facts, moreover, may have to include a wide range of very 'unreligious' facts and the connections may include a number of unreligious categories drawn from sociology, anthropology, politics and other fields as well. Not only is the method of proceeding at issue, so too is the whole notion of a separate class of 'religious facts' which are perceived as 'manifestations' in the well-known manner of Otto, Wach and Heiler. These are isolated, separated out to stand over against the non-religious facts. The advantage claimed for such a separation was that the study of religion could be seen to be an autonomous discipline with its own field and range of material. But, critics pointed out, the price paid for this insistence on autonomy was a heavy one. One is left with the religious manifestations of religious man, but the wide 'context' of human needs and social issues has been left out. We may restate the three points raised under the headings of 'proliferation' of the subject, its enormous growth and complexity which almost precludes any attempt at a systematic account from the start; 'empiricism', starting from the facts, and seeing where they lead to, rather than from a central base and some categories; and 'contextualism', replacing the global system by the social 'Sitz im Leben' [life situation] in which the religious factor is to be found. Let us review these points in turn and consider what may be said in defence of a systematic phenomenology of religion.

(1) Once it is recognised that the systematic concern is but one among many, and that the materials and categories at the disposal of the system-maker suffer from a certain time lag, it becomes a question of whether it is important enough to keep up the attempt. Even those such as Waardenburg (1986) who have distanced themselves from the classical phenomenology are, when dealing with the field in brief compass, forced to bring back many of the basic themes of classical phenomenology such as cosmology, ritual, last things, religious community, initiation, festivals, sacred persons, and so on. What this means is that in place of categories built up and refined over a century of expanding knowledge, we shall have the individual researcher's idiosyncratic categories deriving from a limited area and range of materials. Moreover, with the trend towards contemporary studies, the deep roots of categories tried and tested in the religious developments over centuries and millennia may go unrecognised or be underestimated. One recent area phenomenology and anthropology has, for instance, focused on sacred kingship, but shown little awareness of the other forms of sacred person, or made comparisons with other instances of sacred kings within the sub-category concerned (Olupona, 1983).

(2) The objection that the systematic phenomenology is unempirical certainly ignores the express intention of Heiler from the beginning. 'Das Gebet' [Prayer] (1918) which appeared a year after 'Das Heilige', is offered as an empirical, as well as an historical and a psychological study. It also eschews value judgements and metaphysical interpretations (Heiler, 1918:22). The categories are those drawn from the wide range of religious traditions. Far from being arbitrary, they are the result of an empirical process of finding suitable abstract and general concepts. Both Otto, as well as Heiler, were empirical phenomenologists in the sense that in their travels, daily experience, and reading, they were alert to the religious both in formal religious events and in unlikely customs and incidents. They were in an eminent sense, hermeneutical phenomenologists.

(3) The question of context conjures up the sharpest kind of juxtaposition: on the one hand the global system based on religious manifestations, on the other a regional, limited, social anthropology of religion. Certainly, the emphasis earlier was more on psychology of religion than on sociology, so that a certain shift of emphasis in the direction of the latter field is perhaps overdue. But it is totally untrue to say that the materials and structures of phenomenology are uncontextual. The contexts were amply present at the outset, provided by social anthropology as well as the other disciplines: politics, geography, ethology, ecology, even mathematics, and so on. Non-religious facts are also certainly now part of the picture. Human existential needs are also there. But the process of constructing a systematic overview entails selection and interpretation, distillation and compression. Moreover, the study of religion is not the same thing as social anthropology. It has and must continue to have its own special position. This special position is most clearly visible at the point of the religious systematic, in which the social features only in one category, the sacred community. Similarly, social anthropology has its systematic overview in which religion is but one chapter. Politics has its systematic, economics has its, and so on.

The need for revision and change will always be there, but this should not - indeed cannot - justify abandoning the systematic phenomenology of religion altogether. Even if it is formally abandoned, it must keep on appearing in one guise or another. So why not continue the enterprise in an open and explicit way? If so, of course, hermeneutical phenomenology and the empirical concerns will have to be fostered alongside of the historical work. The categories will have to be checked and revised against the empirical materials, and against the statements of members of the religious tradition concerned whether Buddhist, Islamic, Hindu, Sikh, African traditionist, etc. This can lead to the confirming of the existing category or to the need for a shift in emphasis.

One category that needs to be checked is that of Deity. Heiler's discussion of personalism and impersonalism in the concept of Deity was unexpectedly confirmed for me in Leicester recently. During a lecture series at the University, Dr. Bageshwari Devi expounded Bhaktivedanta's concept of Deity in virtually Heilerian terms, namely through a technical discussion of personalism and impersonalism in the concept of Deity. Similarly, Heiler is willing to accommodate Theravada Buddhism's refusal to entertain any notion of Deity at all, though perhaps more space still could be given to this option, which today is found in Western attitudes as well. Again, under the category of sacred action and sacred silence, more significance could be given to techniques of meditation, while the comments under the concept of salvation (the way of salvation) could be considerably expanded. That Heiler is aware of the importance of ways of meditation is plain not only in the 'Erscheinungsformen' but also in his doctoral thesis, 'Die buddhistische Versenkung' [Buddhist Meditation].

Another point where Heiler's categories might need some modification is where one would expect, in the area of anthropology. Kristensen it is who, in his (own) phenomenology, takes fuller account of the principal life-crisis rituals. Social anthropology's classification of religious rites might also occasion some revision of Heiler's category of sacred action. The latter is divided into the impressive three-fold rites of purification, sacrifice and unification, based upon the sacred action of the Graeco-Roman mystery cults and the inwardness of the medieval mystics. Nevertheless, Heiler does contrive to bring under his category of sacred action an astonishing range of rites.

Further suggestions would include the following: The detailed review of previous phenomenologies and the categories employed by them. Eva Hirschmann (1940) began this task, but it awaits completion by looking at the last forty years. Secondly, the testing of Heiler's phenomenology against the other 40 volumes of history of religion in the massive German series, 'Religions of Mankind'. Thirdly, there is much to be said for testing Heiler's phenomenological categories or those of another phenomenologist of religion against a particular religious tradition. The point here is to see how well the categories stand up and also what sort of profile emerges of the religion under consideration. I myself have tried to test Heiler's categories in this manner. First, I looked at Yoruba traditional religion (McKenzie, 1988a), over a longer period I have made an adaptation of the 'Erscheinungsformen' with special reference to the practices and beliefs of Christians (McKenzie, 1988b).

BARTH, K., 1938. Gottes Offenbarung als Aufhebung der Religion, Die kirchliche Dogmatik, I/2, Zollikon, 321f.
BRENNEMANN, W.L. et al., 1982. The Seeing Eye: Hermeneutical phenomenology in the study of religion, University Park & London, The Penn. State. Univ. Press.
CHANTEPIE DE LA SAUSSAYE, P.D., 1887 & 1889. Lehrbuch der Religionsgeschichte, 2 vols. (E.t. Manual of the Science of Religion, 1891, vol. 1 only)
ELIADE, M., 1949. Traite d'histoire (E.t. Patterns in Comaparative Religion, 1958)
FLASCHE, R., 1978. Die Religionswissenschaft Joachim Wach, Berlin - New York, Walter de Gruyter.
GOLDAMMER, K., 1960. Die Formenwelt des Religisen: Grundriss einer systematischen Religionswissenschaft, Stuttgart, Alfred Kroener Verlag.
HEILER, F., 1961/1979. Erscheinungsformen und Wesen der Religion (Religionen der Menschheit, vol. 1), Stuttgart, W. Kohlhammer Verlag.
HEILER, F., 1918/1969. Das Gebet: Eine religionsgeschichtliche und religionspsychologische ntersuchung, Munich.
HIRSCHMANN, E., 1940. Phenomenologie der Religion: Eine historische-systematische Untersuchung von "Religionsphenomenologie" und religionsphenomenologischer Methode in der Religionswissenschaft, Würzburg-Aumühle, Konrad Triltsch.
KAUFMANN, W., 1976. Religion in Four Dimensions: Existential and aesthetic, historical and comparative, New York, Reader's Digest Press.
KRISTENSEN, W.B., 1960. The Meaning of Religion: Lectures in the phenomenology of religion, The Hague, Martinus Nijhoff.
LEEUW, G. van der, 1933. Phanomenologie der Religion (E.t. Religion in Essence and Manifestation, 1938/1964).
LEEUW, G. van der, 1938. Rudolf Otto und die Religionsgeschichte, Zeitschrift für Theologie und Kirche, 1938, 71-81.
LEHMANN, E. (with A. Bertholet), 1925. Lehrbuch der Religionsgeschicte, 4th. ed., 2 vols.
MARVELL, J., 1985. The English Place of Worship: A phenomenological study, Leicester, Ph.D.
MCKENZIE, P.R., 1988a. The phenomenology of Yoruba Religion, Africana Marburgensia.
MCKENZIE, P.R., 1988b. The Christians: Their practices and beliefs - an adaptation of Friedrich Heiler's phenomenology of religion, London, S.P.C.K.; Nashville, Abingdon.
MENSCHING, G., n.d. Die Religion: Erscheinungsformen, Strukturtypen und Lebensgesetze, Munich, Wilhelm Goldmann Verlag.
MISNER, P. (ed.), 1981. Friedrich von Hugel, Nathan Soderblom, Friedrich Heiler: Briefwechsel 1909-1931, Paderborn, Verlag Bonifatius-Druckerie.
OLUPONA, J.O.K., 1983. A Phenomenological/Anthropological Analysis of the Religion of the Ondo Yoruba of Nigeria, Boston Univ. Ph.D.
OTTO, R., 1932. Das Gefühl des ـberweltlichen (sensus numinus), Munich, C. H. Beck.
SCHUTTE, H.-W., 1969. Religion und Christentum in der Theologie Rudolf Ottos, Berlin, Walter de Gruyter.
SHARPE, E.J., 1975. Comparative Religion: a history, London, Duckworth.
SHARPE, E.J., 1983. Understanding Religion, London, Duckworth.
SHARPE, E.J., 1987. Universal Religion for Universal Man, the Charles Strong Lectures 1972-1984, ed., R.B. Crotty, Leiden, Brill, 157-171.
WAARDENBURG, J., 1986. Religionen und Religion: Systematische Einführung in die Religionswissenschaft, Berlin - New York, Walter de Gruyter.
WACH, J., 1924. Religionswissenschaft: Prolegomena zu ihrer wissenschaftstheoretischen Grundlegung, Leipzig.
WACH, J., 1927. Idee und Wirklichkeit in der Religionsgeschichte, Zeitschrift für Theologie und Kirche, 1927, 334-364.
WACH, J., 1972. Types of Religious Experience: Christian and Non-Christian Chicago, University of Chicago Press, esp. chap. 10.