The occurrence of certain lacunas in the genesis investigation of theoretical fundamentals of the historical (diachronic) phonology is, to a certain degree, a result of a scant attention paid to the synchronic phonological researches. The Prague school scientists stated that the best way to study the nature and character of the language was the synchronic analysis, without which it was impossible to study the language diachronically. Working within the synchronic framework, the Moscow and Saint Petersburg phonological schools developed and upgraded such crucially important in phonology notions as phoneme, differential characteristics (signs), allophone, variability, correlation, neutralization, etc. It comes as no surprise that V. I. Postovalova, Yu. Ya. Burmistrovich as well as the others scientists pointed out the primary significance of the mentioned notions to the historical phonology [10, p. 85; 4, p. 23–27].

The works analysis of the scientists of the Moscow and Saint Petersburg phonological schools was carried out by a great amount of prominent linguists in particular A. A. Reformatskiy, P. K. Vaarask, S. V. Protogenov, V. K. Zhuravlev and others. Nevertheless, there are no special linguistic historiographical works dedicated to the in-depth study of the scientists’ phonological concepts of the mentioned schools with the identification of their further influence on the historic phonology development, and that explains the scientific topicality of our article.

The objective of the article is to carry out a linguistic historiographical analysis of the Moscow and Saint Petersburg schools phonological heritage within the framework of the modern historical-phonological conceptions.

To meet the established objective we need to accomplish the following tasks: 1) to define the notions especially significant to the historical phonology, which were developed in synchronic phonology; 2) to analyze the phonological concepts of Moscow and Saint Petersburg schools scientists; 3) to find the links with the historical phonology.

We need to pay a special attention to the establishment of the methodological difference between Moscow and Saint Petersburg schools representatives in their phonological study of language facts. Thus, the application of the morphological principle for synchronic phonology studying is characteristic of the Moscow phonological school; the psychological and acoustic-physiological aspects are predominant in Saint Petersburg scientists’ researches. The non-recognition of the morphological principle by the scientists of Saint Petersburg phonological school gave grounds for the criticism of their phonological conception.

The concept of phoneme was central to the evolution of phonological science. The detailed analysis of the phonological theories based on the different interpretations of the phoneme conception was given in the work of R. O. Jakobson. The linguistic historiographical analysis of the phonological theories was carried out by Yu. A. Levitskiy, S. V. Protogenov and others. As V. K. Zhuravlev pointed out that psychological and physiological aspect of phoneme falls within the scope of the Saint Petersburg phonological school theoretical interests [5, p. 8]. The psychological interpretation of the phoneme concept as a semantic peculiarities bearer was proposed by L. V. Shcherba [13, p. 116, 132]. The doctrine on the semantic distinction and development of acoustic-physiological characteristics of the sound was assumed as the basis of the phoneme notion by the following representatives of the Saint Petersburg school such as L. R. Zinder, M. I. Matusevich, A. N. Gvozdev [6, p. 35, 51]. L. V. Shcherba also pointed out an interesting fact about the allocation of an independent phoneme. The linguist considered that the independent phoneme in the language system was not equal to the sound as the phonemes can be expressed by the sound combination, for example of any consonant and a vowel, coined a syllable (syllable-phoneme in comparison to V. K. Zhuravlev group-phoneme) [14, p. 116]. The theory of phoneme developed by the Saint Petersburg school became a base for experimental phonetics and typology.

Thanks to the Moscow linguist N. F. Yakovlev and his positional phonology, the phoneme theory was not any more exposed to the influence of psychologizm [5, p. 11–12; 9, p. 102].The morphological principle and phonetic position became leading ones in the phoneme definition by the scientists of the Moscow phonological school [9, p. 94]. The phoneme is a totality of alternating sounds [1, p. 7]. The allocation of independent phonemes on the ground of phonemes unity was very characteristic of the Moscow scientists and showed also a considerable promise in the further resolution of the problem of language phonemic segmentation. The phonologists of the Moscow school paid also a great attention to the establishment of the inter-level relations in language.

The long-standing question as to what was the difference between speech sounds was tackled across the generations of linguists. After the phoneme theory founding there was a great range of questions concerning phoneme features identification, its classification and functional value. The scientists of the Moscow and Saint Petersburg phonological schools continued their investigations of the phoneme features within the framework of functional aspect. Thus, L. V. Shcherba considered differential (typical) features as the most important for the phoneme allocation [13, p. 120]. And in respect to that the linguists denoted phoneme as totality of differential features [11, p. 18].

The thesis on the importance of non-differential (integral) features consideration is very characteristic of the Moscow school representatives. Nevertheless, L. R. Zinder supported the same view, defining “the establishment of the wide range of the phoneme tones” as the main function of the non-differential features [6, p. 40].

The more detailed study of the problem was given in the works of A. A. Reformatskiy. The scientist divided the phoneme features on differentials and integrals and herewith singled out the importance of considering functional load of integral features, suggesting a hypothesis on different levels of integrality [12, p. 245–248]. In accordance to the hypothesis the further allocation of integrals-potentials (they can be called potential differentials) was crucial for the development of diachronic phonology [11, p. 28]. Dealing with non-differential (excess) phoneme features O. S. Ahmanova points out, firstly, the ambiguity of distinguishing differential and non-differential features, and secondly, in some special position the excess phoneme feature can be the only way to differentiate (for example, opposition sonority / voicelessness, that is differential for the Eastern-Slavic languages, in a whisper change into opposition weakness / strength that is an excess feature for the phonological systems of the given languages) [2, p. 35].

Sounds are extremely diverse in human speech, but they cannot be extremely diverse in the language, said A. A. Reformatskiy [9, p. 91]. The significance of distinction of the notions such as sound of speech and sound of language was pointed out by P. S. Kuznetsov, M. V. Panov and others [7, p. 28–39; 9, p. 91–92]. Distinguishing between the language and the speech was typical for the works of representatives of Moscow and Saint Petersburg linguistic schools, which accounted for the singling out the phoneme as a unit of language and the sound as a unit of speech. It is in this area that the phonetic and phonily are interfaced (L. V. Scherba, P. S. Kuznetsov, A. A. Reformatskiy etc.). According to M. V. Panov, the introduction of a dynamic aspect as a part of characteristics of the sounds of language helps find the way these sound can function and define the subject of phonology [9, p. 90–91].

Treating the phoneme as a changing essence (defining the phoneme variation as typical features for the studies of Moscow and Saint Petersburg linguistic schools) is very important for our investigation. It is generally accepted that the scheme of historical changes in the phonological system starts from allophone variation. In developing the contest of historical changes in the phonetic system of a language, L. V. Scherba pointed out that the phonetic history of a language can be reduced “from one side, to the disappearance of some phonetic differences and some phonemes, and on the other hand it can bring to understanding some shades and appearance of new phonemes” [13, p. 123]. The process of phonologization of allophones and appearance of new phonemes was represented by L. R. Zinder as “a distribution of shades composing one phoneme in two different ones” [6, p. 57, 77].

Sounds of speech through which the phonemes are realized, are considered by scientists sometimes as shades of phonemes (L. V. Scherba [13, p. 122, 132]), sometimes as variants and variations (R. І. Аvanesov, P. S. Кuznetsov [12, p. 252–253]) and even as sounds row which alters regularly (V. М. Sidorov, М. V. Panov [9, p. 106]). It should be noted that the description of the phoneme as a unit of sounds altering in positions can also be found in modern explanations of the phoneme and its allophones.

Among the variances of the shades of a phoneme (optional and compulsory variants) L. V. Scherba and L. R. Zinder single out one and the most typical shade which occurs in an isolated position. It is the only element of speech which is perceived by the speaker, being typical for a certain phoneme, but not identical to it [13, p. 119, 132; 6, p. 40–42, 69].

The study of the problem of phonemes and their variants by Moscow and Saint Petersburg linguistic schools is closely linked to the concept of position which is the leading principle for the phonological concept of Moscow linguists [12, p. 115]. Thus, R. І. Аvanesov, V. М. Sidorov single out two types of sound attributes [2, p. 22]. According to their theory, there are independent sound attributes which do not depend on their phonetic surrounding (strong position; position of maximum, P. S. Kusnetsov) and there are those which depend on the phonetic surrounding (weak position, position of minimum, P. S. Kusnetsov) [the same, p. 250]. In the first case, as Moscow linguists believe, we deal with a phoneme, while in the second one – we deal with its derivatives (variations and variants) [the same, p. 116–117, 252–253]. The scientists introduced also the concept of a main type of the phoneme (ex., the most characteristic feature as defined by Saint Petersburg linguistic school), which is characterized by the smallest dependence on the phonetic surrounding and occurs in the most strong position [the same p. 250–251]. It is the strongest phonemes which, according to R. I. Avanesov and L. V. Scherba, create the phonetic system of a language [the same, p. 251–252; 9, p. 193]. M. V. Panov believed that using a functional aspect to define the composition of phonemes by Moscow and Saint-Petersburg linguists, was a very important step for the further development of phonology [9, p. 193].

According to A. A. Reformatskiy the position is not an important factor for the phoneme in general, but it turns out to be an essential element for its differential features (differentials) [12, p. 245–248]. This thesis appears contrary to the opinion of representatives of Moscow linguistic school on phoneme who like V. M. Sidorov for example, believed that the last indivisible element was a sound as an identifier of phoneme and not as its feature [9, p. 190]. The strong position is determined by A. A. Reformatskiy as a totally free one [12, p. 245–248]. Expanding the classification of phonemic positions, the linguist points out among the strong and weak ones also the positions which are structurally and contextually determined [the same]. Another interesting consideration of A. A. Reformatrskiy is on the possibility of transformation of a strong position into a weak one, according to which the history of phonological system is interpreted is as a qualitative change of positions [the same, p. 119], which results in the dephonologization of positions, as V. K. Zhuravlev believes [5, p. 54]. Making a distinction between perceptual and significant positions, practiced first by A. A. Reformatrskiy [1, p. 8], was continued in the works of M. V. Panov who in terms of phonetic surrounding distinguished between perceptively strong and weak positions, while in terms of neutralization process the positions could be significantly strong and weak [9, p. 115–117]. R. I. Avanesov shared M. V. Panov’s point of view that such a classification of positions makes it possible to give a clear definition and to improve the concept of variation and variant [3, p. 80].

In searching the reasons of appearance of different shades of a phoneme L. V. Scherba was able to define the phonetic surrounding as on the major factors in this process [13, p. 157]. For Saint-Petersburg linguistic school the prevailing was the idea of substitution of sounds in the identical positions rather than the change thereof as it was thought by their Moscow colleagues. From our prospective, this was a weak-point and the reason why the ideas of Saint-Petersburg linguists turned out to be less attractive for the modern historic phonology.

The consecutive adhering to the systemacity principle was typical for the research works by Moscow and Saint-Petersburg linguistic schools [12, p. 163, 249; 10, p. 59–60]. The thesis about the phoneme as a system element was leading for the scientists of these schools. A. A. Reformatskiy believed that the language always remains systemic and structured both in synchrony and diachrony. [8, p. 38].

Results of researching activity in the field of structural organization of phonological system (oppositions and correlations) are provided in the works of R. I. Avanesov, A. A. Reformatskiy and others. Developing an idea that all phonemes in the language constitute a unified system of contrasts, L. V. Shcherba underlines that both single phonemes and their groups can be opposed [13, p. 134]. As an opposition member the phoneme was also interpreted by the linguists of Moscow scientific school. The concept of correlation (opposition system) necessary for singling out the phonemes was developed by P. S. Kuznetsov [12, p. 158].

According to some linguists, for example S. V. Protogenov and M. V. Panov, a deep study of phonological oppositions and processes of their neutralization was a particular feature of Moscow phonological school [11, p. 28; 8, p. 113–114]. Thus, for A. A. Reformatskiy the neutralization stands in the loss by phoneme of its valence (set of differentials) and occurs in the weak position [12, p. 245–246].

S. V. Protogenov believes that it was the study of position and neutralization aspects that made Moscow school linguists introduce a more generic concept of phoneme comparatively to the existing one in that period [11, p. 29]. In view of the functional load of each phoneme in the system, P. S. Kuznetsov introduces the notion of hyperphoneme (M. V. Panov developed a theoretical basis of this notion) [9, p. 119–121]), for which the criterion of functionality is the main and this distinguishes the hyperphoneme from the archiphoneme of Prague linguists. A. A. Reformatskiy speaks about the row which is made of the principal kind of phoneme and all its variants. R. I. Аvanesov accomplished this statement introducing the notion of a phonemic row [11, p. 29]. According to P. K. Vaarask, all these notions could be combined in one concept – hyperphoneme. O. S. Ahmanova underlines that the neutralization process causes the appearance of particular units of the sound system which belong to more generic types and these can be called archiphonemes or hyperphonemes with no difference in the meaning [3, p. 9–10]. According to O. S. Ahmanova, the terms phonemic row, mixed phoneme and some others correspond more to real sounds while the notion of archiphoneme is abstractive [the same]. If we step back from real ideal constructions, only real connections between the phoneme and its shades will be seen as it was underlined by L. V. Scherba [the same, p. 11–12].

The investigation of neutralization was of a primary importance for the increasing of explanatory level of historical phonology. According to V. K. Zhuravlev, the neutralization mechanism in synchrony is the first step of convergent-divergent processes as well as processes of opposition phonologisation and dephonologisation [5, p. 213]. The neutralization is the link between synchronic and diachronic phonology [the same].

The study of grammar alternations by I. A. Baudouin de Courtenay and М. V. Krushevskiy gave a start to the development of morphology as a separate scientific discipline. L. V. Scherba distinguished the alternation by analogy, treating it in from a psychological point of view [13, p. 115]. An expanded classification of positional and non-positional alternations is given in the works by R. І. Аvanesov and М. V. Panov [9, p. 97–106]. It is interesting to know that the scheme of phonetic positional alternations proposed by М. V. Panov corresponds to the formula of the phonetic row law by V. К. Zhuravlev [the same, p. 104–105].

Thus, the sounds alternations according to the positions have a synchronic character and the sounds which alter in various positions represent the same phoneme. When the parameter of position does not effect, and the alternations of sound become position-dependent (historical), here comes the factor of diachrony and alternating sounds belong, іn that case, to different phonemes. This helps to make a conclusion that the positional alternations according to Moscow linguistic school representatives are a preparation step to the phonologic process of divergence which has a diachronic character.

V. К. Zhuravlev underlines that Moscow school linguists didn’t create a proper historical-phonological concept [5, p. 23]. The same can be said about Saint-Petersburg linguistic school. But they made success in developing the theoretical aspects of general phonology without which the historical-phonological study of the sound system of language is impossible. At the same time such notions as variation and neutralization which were deeply studied by linguists of Moscow and Saint Petersburg schools, belong to the group of notions regarding the chance of phonematic essence and are used in the historical phonology.

The use of phonologic ideas in the study of Eastern-Slavic languages (mainly Russian language and its dialects) by Moscow and Saint-Petersburg linguistic schools made a foundation for the historical study of phonological systems of respective languages. That is why the analysis of contributions made by the linguists of these schools in the practical study of phonological systems of the subgroup of Eastern-Slavic languages results promising for the phonology of East Slavic languages.