At present there may be differences in opinions as to the nature of ethnographical phenomena in general, nor as to their complexes and elements. They are observable manifestations of required knowledge, practices, and behaviour. These are either transmitted from one generation to another, or borrowed from neighbours, or even created by the individuals who compose ethnical units, which, like any other population possess a series of inherited physio-psychological complexes, the latter leaving possibilities for and putting limitations on creation of ethnographical phenomena. They are thus of a purely psychological and mental character, being a form of human adaptation as the latter is observed in the human units resulting from the process which I call ethnos. Ethnographical phenomena, in complexes and in elements are functions and as such they cannot be understood in their static abstractions, so that description of an ethnographical complex, and consequently elements, forming the complex, presumes necessity of penetration into the mechanism of this function.
Since the ethnographical complexes cover a great number of cultural elements they must be classified in some way, for their description and even for their observation. The classification of the ethnographical elements and complexes into groups of material (or technical) culture, social organization, and «psychomental» complex is strictly technical; as I have already pointed out in my work dealing with the social organization of the Northern Tungus, the phenomena of material culture, social organization and psychomental complex form a certain system, a well balanced complex, in which all elements are more or less «adjusted» and thus they cannot be treated independently one from another. In this aspect of the problem we may consider complexes as interacting which expression cannot be taken literally for the cultural elements as such do not act, but the populations are acting. These remarks may suffice for showing my point of view, namely, in the treatment of the psychomental complex the grouping of ethnographical elements into these three headings is done only in view of the exposition of facts which must be classified in some way.
By the term «psychomental complex» I name here those cultural elements which consist of psychic and mental reactions on milieu. Milieu as a whole and in its elements is a changeable or stable, dynamic or static. For convenience of treatment these elements may be classified into two groups, namely, (1) a complex of reactions of a permanent and definite character, though they vary within a certain range, and (2) a complex of ideas which define certain mental attitudes and which may also be regarded as a theoretical system of the given unit (or even person). The psychomental complex of a unit as it is a function is also responsible for the functioning of the population unit as a whole. The functioning of this assures, or better, merely manifests existence of the unit. In fact, the psychomental complex as a function of adaptation to the variable milieus, makes the unit sensitive enough, both by rigid resistance and a flexibility, for production of reactions.
Indeed, the ethnographical facts gathered and presented here are phenomena of a special character. In the case of the material culture there are physical objects to be described, photographed, recorded, and analysed; in the case of the social organization there are relations which may be described as a fixed complex of practices; while in the case of psychic and mental elements, which form the psychomental complex, the description is confined to the attitudes and ideas, and only partly to the description of behaviour, customs and practices, which may be recorded and rarely photographed. So as material they greatly differ from other ethnographical groups. This is one of the additional reasons for treating them separately although I shall always refer to their connection with the material culture and the social organization. The element of the psychomental complex, as compared with those forming the complexes of material culture and social organization, are sometimes less stable; and at the same time — when taken separately — they are more numerous and of lesser importance. In fact, the elements which constitute, for instance, the present theory of posthumous life may change, even the entire complex may change and not affect other elements of the ethnographical complex. Also, the acquisition of knowledge held responsible for the change of some elements of the material culture may be easily accepted or rejected and not produce any harmful effect on the whole. The same may be stated with reference to aesthetic manifestations. However, these remarks cannot be spread over the phenomena of a purely psychic order in a narrow sense of the phrase. Variations and instability of the elements of the psychomental complex are very general, — they are very often borrowed from neighbours, especially when they are not in a crying contradiction to the existing complexes. For instance, European science, which has become almost universal, is one of cases of instability of the psychomental complexes amongst the ethnical units bound by the interethnical pressure of the European ethnical complex. Under the condition of restricted intercourse between the ethnical units and lesser interethnical pressure, the stability of complexes in general, and psychomental complexes in particular, is much higher than in the case of groups living beyond a strong pressure. This may also be shown from the general principle of impulsive variations.