Ideas about the structure of the firmament in the worldview of an Orthodox Christian of the X–XVII centuries (based on canonical and apocryphal texts)

Franchuk Oksana Valer'evna ORCID: 0000-0002-7645-0177 PhD in Philology Associate Professor; Department of Russian Language, General Linguistics and Mass Communication; Magnitogorsk State Technical University named after G.I. Nosov 455000, Russia, Chelyabinsk region, Magnitogorsk, Lenin ave., 26, office 206 oxana.franchuk@mail.ru Derevskova Elena Nikolaevna ORCID: 0000-0001-5746-4656 PhD in Philology Associate Professor; Department of Russian Language, General Linguistics and Mass Communication; Magnitogorsk State Technical University named after G.I. Nosov 455000, Russia, Chelyabinsk region, Magnitogorsk, Lenin ave., 26, office 206 august1667@mail.ru

Podgorskaya Anna Vyacheslavovna ORCID: 0009-0000-4449-6691 PhD in Philology Associate Professor; Department of Russian Language, General Linguistics and Mass Communication; Magnitogorsk State Technical University named after G.I. Nosov 455000, Russia, Chelyabinsk region, Magnitogorsk, Lenin ave., 26, office 206 podgorsky_a@mail.ru

In modern linguistics, new trends have emerged in the study of conceptual structures and the identification of different types of concepts. One of the mental formations characteristic of both naive and religious worldviews is the idea of the structure of the world and the place of man in the global structure of the universe.

The Russian model of the world order has changed significantly in different historical periods. The oldest written monuments available to modern science do not allow us to fully recreate the original Slavic cosmology of the pre-Christian period. It is only partially possible to reconstruct it on the basis of secondary written, folklore and material sources. After the Baptism of Rus, the ideas of the Slavs about the structure of the universe were closely connected with the Christian doctrine of the creation of the world and the Christian views on the existence of the Earthly World and the Heavenly World. However, the stories about the origin of the world were set out in those books of the Old Testament, which, according to scientists, were not among the texts translated into Old Slavonic in the 9th–11th centuries. The first translations of all books of the Old Testament canon were made only in the XV century, and the complete Synodal translation of the texts of Holy Scripture was carried out in the XVIII century. It can be assumed that the acquaintance with Christian cosmology was carried out in schools opened at temples and monasteries after the adoption of the new creed. Perhaps the legends about the structure of the universe were brought from distant lands by travelers and pilgrims: stories about the world order could be part of spiritual poems and epics sung by travelers and wandering magicians. Besides, after the adoption of Christianity, not only canonical Christian texts began to appear on Russian soil. Ancient Russian scribes also knew apocryphal works, materials on astrology, fortune-telling and medicine. Despite the prohibitions of these books by the Orthodox Church, innermost thoughts about the cosmos and man's place in it developed in Ancient Russia. The object of our research is linguistic units that represent the ideas of the Slavs about the structure of the firmament. The material for the analysis was canonical Christian texts (books of the Old Testament and the New Testament), monuments of the Old Slavonic language with texts of the Gospels, as well as non–canonical texts reflecting cosmological concepts of the X-XVII centuries.

Let us characterize the representation of the concept of "Heaven" in the texts of Holy Scripture.To restore a fragment of the religious worldview of the medieval Slavs, it is necessary first of all to refer to canonical biblical texts and determine the specifics of their use of linguistic units representing the concept of "Heaven".

The name of the concept noun heaven is used in the texts of the Holy Scriptures in several meanings. First, the sky is the upper part of the universe, the visible airspace above the horizon. This meaning is reflected in dictionaries compiled on the basis of the oldest Slavic monuments ^{[1, p. 944]}; ^{[2, p. 359]}. An example of such a perception of the lexeme heaven is the lines of one of the chapters of Deuteronomy "All the nations under the whole heaven" (Deuteronomy IV:19), which can be interpreted as "all the nations under one heaven" or "all the nations on earth." The same understanding of the noun heaven is recorded in the Supraslaus manuscript: ^{[3, p. 545]}.

Secondly, the sky in the biblical texts is also called the aerial sphere, within which the Sun, Moon, stars and other celestial bodies are located. Such ideas about the semantics of the noun heaven are reflected in the books of the New Testament and were recorded in the Old Slavic written monuments: (Matthew 24:29) ^{[4, p. 235]}.

In the Bible, heaven can also be called an invisible, insubstantial world – a holy place where God and angels are present.: "Then hear from heaven, from your dwelling place, their prayer and supplication, and do what is necessary for them" (3 Kings. 8:49); "Our Father who art in heaven" (Matthew 6:9; Luke 11:2).

It should be noted that the nouns veil (Job 38:17), canopy (Isaiah 40:22), scroll (Revelation 6:14) or the stable phrase vessels of heaven (Job 38:37) are used to refer to the firmament in the books of the Old Testament and the New Testament. This perception of the air sphere reflects the planar-mosquito concept of the world order, according to which the universe consists of a flat inhabited land inhabited by living beings and an atmosphere in the form of a vault or thin fabric spread over the land.: "He spread out the heavens like a fine cloth, and spread them out like a tent for habitation" (Isaiah 40:22); "I–My hands spread out the heavens" (Isaiah 45:12).

According to the ideas of the ancients, the firmament had the shape of a dome or tent and was a kind of dense substance. The Psalm of David on Genesis says: "You clothe yourself with light like a robe, you stretch out the sky like a tent of leather" (Psalm 103:2). The Book of Job says: "Did You spread out the heavens with Him, solid as a cast mirror?" (Job 37:18).

Perhaps these ideas were reflected in the designation of the firmament by the noun firmament in the texts of Holy Scripture. We read the following about the second day of creation: "And God said, Let there be a firmament in the midst of the waters, and let it separate the waters from the waters. And so it became. And God created the firmament; and He separated the waters that were under the firmament from the waters that were above the firmament. And so it became. And God called the firmament heaven. And God saw that it was good" (Genesis 1:6-8).

The Complete Dictionary of the Church Slavonic language states that the firmament is the visible space of the firmament containing stars and "formed between various balls or bodies on the second day of creation" ^{[5, p. 710]}. Blessed Theodoret explains the origin of this name by the consistency of the firmament or its dense and stable state "because it was composed of a liquid being of waters, which condensed and became solid" ^{[5, p. 711]}.

According to modern interpreters of the Old Testament, the use of the lexeme firmament in this context is related to the peculiarities of the Synodal translation of the Old Testament books from Greek and Hebrew. Archpriest A. Sorokin notes that in the original version, these verses of the first chapter of Genesis contained the Hebrew word rakia, which literally translated as ‘dome", "firmament" or ‘space". "In the Greek translation, the word stereoma appears with the meaning 'stronghold, fortress, support'. As you can see, there is a moment of hardness, reliability, and some kind of fixity. Indeed, the sky above us seems to be something solid, fixed, like a ceiling" ^[6].

Priest R. Posypkin notes that the lexeme firmament, which functions in the biblical context in the meaning of 'heaven, cosmos', is a metaphor: "God calls the cosmos the firmament because, compared with 'nothing' that existed before the beginning of creation, it (firmament, heaven, cosmos) is material, that is, created."" ^[7].

Difficulties with the perception of heaven as a firmament are explained by the fact that the system of concepts reflecting the dogmas of the Christian faith was borrowed by Russian culture as a single integral structure. Researcher of Russian Orthodox discourse L. N. Churilina rightly notes: "The tasks of the translator of the Holy Scriptures included following the Truth, or the adequacy of the conceptual sphere, rather than adapting to a new language system and, more importantly, to the native worldview of native speakers of this language" ^{[8, p. 380]}. When translating from one language to another, metaphors are the most difficult element of the text. The text of Holy Scripture demonstrates "a high degree of freedom from language – it is literally permeated with metaphor, and therefore does not accept literal reading" ^{[9, p. 177]}. In this regard, the identification of the meaning of this metaphor requires the involvement of special sources containing both the interpretation of the biblical texts themselves and additional information on the origins of Christian cosmology.

Despite the existence of controversial interpretations of the semantics and etymology of the name firmament to denote the firmament, we can state the fact that this metaphor was well known to Orthodox Christians and was part of the field of verbalizers of the concept of "Heaven". This is confirmed by the fixation of the stable verbal complex firmament of heaven / both by the dictionaries of the Old Slavonic language ^{[2, p. 693]}; ^{[10, p. 936]}; ^{[11, p. 445]}; ^{[12, p. 326]}, and the dictionaries of the Russian language of the XIX–early XX century. XXI centuries ^{[13, p. 394]}; ^{[14, p. 662]}; ^{[15, p. 535]}; ^{[16, p. 488]}.

Some ancient cosmological myths are characterized by the idea that there are several levels of the firmament. Perhaps the presence of the plural form of the noun heaven can be considered an echo of these views. In the myths and legends of the peoples of the world, we are talking about a different number of heavens (three, seven, eight or ten).

Christian theologians are still debating whether there is a mention in the biblical texts of the heterogeneity of the firmament and the existence of several tiers or steps in it. Classical biblical texts do not clearly differentiate the celestial space. However, in the works of the Church Fathers, one can find statements about the need to distinguish between ideas about heaven as an ideal Divine world and the firmament of heaven: "There, on the height of heaven, is a holy special place of God's omnipresence; there is His throne, there He walks in a heavenly circle" (Job 22:14) ^[17]. Therefore, the biblical text allows us to state the existence of two levels or tiers of the firmament. One of them is accessible to the human eye, is made of material and looks like a dense roof or dome. The second level is the spiritual invisible sky, incomprehensible to humans.

It follows from this that in the Old Testament, when describing the second day of creation, it refers specifically to the lowest level of the firmament (the firmament of heaven), as well as the appearance of stars and luminaries on it on the fourth day of creation: "And God said, Let there be luminaries in the firmament of heaven to separate the day from the night, and for signs, and times, and days, and years. And God created two great luminaries: the greater luminary to control the day, and the lesser luminary to control the night, and the stars. And God set them in the firmament of heaven to give light on the earth" (Genesis 1:14-18).

The upper heaven serves as the abode of God and is referred to in the Christian tradition as ^{[12, p. 354]}. The idea of a Christian paradise, where people who lead a righteous lifestyle go after death, is connected with the ideas of the heavenly abode of God. Dictionaries of the Old Slavonic language record stable verbal complexes for denoting the inhabitants of the highest heaven: angels of heaven, angels of God, angels of the Lord, angels of the Holy Spirit ‘disembodied spiritual beings created by God before the creation of the visible world and man’, ‘perfect spiritual creatures in the service of God’ ^{[18, pp. 43-47]}; voe (voi) heavenly (heavenly) ‘heavenly warriors, soldiers of God in the heavenly kingdom' ^{[19, p. 86]}, heavenly host ‘angels, army of the heavenly kingdom’ ^{[1, p. 942]}, heavenly forces ‘heavenly forces, angels’ ^{[1, p. 942]}.

In theological writings, one can find the idea of the existence of a third level of the firmament. Supporters of this version refer to the Epistle of the Apostle Paul: "I know a man in Christ who was fourteen years ago (whether in the body, I do not know, or out of the body, I do not know: God knows) he was caught up to the third heaven" (Second Epistle to the Corinthians XII:2). However, modern interpreters of the Holy Scriptures state: "The Apostle Paul does not say that there are three heavens or three levels of heaven. In many ancient cultures, people used the term "heaven" to describe three different "realms" – heaven, outer space, and spiritual heaven. Paul said that God took him to the "Divine" heaven, the sphere of God's dwelling" ^[20].

It should be recognized that neither the classical biblical texts nor the writings of the Church Fathers provide an unambiguous answer to the question of the structure of the firmament and the existence of one or more levels of the celestial sphere.

Let us describe how the ideas about the celestial spheres were reflected in non-canonical texts.It was not only canonical biblical texts that influenced the formation of the Orthodox Christian's worldview. Apocrypha, which satisfied various spiritual needs, were very popular in Russia. The first texts of the apocryphal books were translations from Greek, but the proof of the popularity of the apocrypha in the Russian land is the penetration of apocryphal plots into Old Believer literature, into folk spiritual verse, as well as the inclusion of some apocryphal texts in ancient Russian chronicles and liturgical collections along with the lives of Christian saints. Researchers of apocryphal texts note that most of the apocrypha did not contradict the canon, but on some issues they gave different interpretations from the orthodox point of view. Therefore, "translated ancient Russian apocrypha can serve as a basis for studying the national worldview, as well as for observing the "Russification" of Christianity, its adaptation to local, purely Russian conditions" ^{[21, p. 8]}.

Many lists of apocrypha became widespread among the people due to the fact that in them it was possible to find simple and understandable answers to questions that were bypassed by the Holy Scriptures, but of interest to Orthodox Christians. Perhaps one of these important questions for understanding was the existence of one or more stages of the celestial space.

Already in the first translated apocrypha, one can find information about the structure of the world, the structure of the firmament, the different levels of the heavens and their inhabitants.

One of the apocryphal texts containing cosmological views was the "Six Discourses on the Universe," known in Russia as the "Shestodnev / Shestodnevnik" and written by the Syrian theologian, preacher, Bishop Severian of the city of Gabala. Severian of Gabala lived in c. IV–the beginning. He was a member of John Chrysostom's inner circle. The first excerpts of the "Six Days" appeared in Russia in the translation of John the Exarch of Bulgaria in the XII century, and the full versions of the monument date back to the XV–XVI centuries. To date, there are more than 50 lists of Severian's text, as well as many extracts and compilations, testifying to the great importance of the ideas outlined in it for ancient Russian literature.

In the first Word of the "Six Discourses on the Universe," the author explains the creation of the world, and also talks about the appearance of heaven and the firmament: ^{[22, p. 96]}.

Severian Gabalsky offers the reader an understandable visual image: he compares the universe to a house or building that has two upper floors – a ceiling and a roof. The highest heaven (the upper heaven, the heaven of heaven) was created on the first day of creation and was located above everything. On the second day, God created a similar overlap in the middle of the lower sky (visible), above which He placed the waters. The visible sky consisted of cooled waters and represented Exactly the real sky, not the mountain, but the visible sky in the biblical tradition is called the firmament. The author of "Six speeches about the universe" gives his own etymology of this name: ^{[22, p. 98]}. One never speaks of a solid object as "established" or "solidified": ^{[22, p. 103]}.

According to the Bishop of Gabala, the waters spilled over the firmament were designed to protect the ice firmament from the heat of the heavenly bodies: ^{[22, p. 99]}. Another purpose of the waters located above the icy firmament was to reflect the sun's rays and the light of other celestial bodies to illuminate the earth's surface: ^{[22, p. 100]}. Researcher of apocryphal texts V. V. Milkov notes: "In this case, Severian reproduces the opinion established in ancient natural philosophy that the whole world, by its nature, always goes only upwards. It follows from his constructions that if there were no firmament reflecting the rays downwards, the whole world would be plunged into darkness" ^{[22, p. 88]}.

Trying to clearly differentiate the concepts of "visible sky" / "higher sky" and make them very clear to the reader, Severian Gabalsky compares the firmament with the head. The first (higher) sky in the text of the monument is likened to the brain invisible to humans, and the second sky (firmament) evokes associations with the palate accessible to vision and located above the visible tongue (a horizontal partition separating the oral cavity from the nasal cavity): ^{[22, p. 100]}.

Describing the structure of the firmament, Severian Gabalsky gives different versions about the shape and composition of the sky: ^{[22, p. 101]}. The author of "Six Speeches about the universe" comes to the conclusion about the domed (mosquito) shape of the sky on the first day of creation and the flat shape of the firmament. He proves that the heavenly bodies move along a horizontal trajectory and never move underground. The arguments of Severian Gabalsky allow us to consider his views in line with the plane-mosquito cosmological concepts known to ancient Russian scribes in the XII–XVII centuries.

According to researchers of apocryphal texts, geocentric ideas of the world order were already widespread in Russia in the pre-Mongol era. The texts of one of the largest systematizers of Christian dogmatic theology of the 8th century became the main guides of the geocentric worldview. St. John of Damascus. The works of John of Damascus were translated into Old Slavonic in the 9th–10th centuries. They were also popular with ancient Russian scribes in the 12th century.

The theological and philosophical treatise "The Source of Knowledge", which in the ancient Russian tradition was known as "Theology", interprets a fairly clearly constructed geocentric scheme of the world order and characterizes all the elements of the universe. A special place in the text of the treatise is given to the description of the aboveground space (chapter "On the sky").

John of Damascus dwells in detail on the different interpretations of the concept of heaven in the text of Holy Scripture: ^{[23, p. 61]}. The author of Theology considers the second heaven or firmament to be the extreme limit of the material sphere accessible to human perception. The systematizer of the texts of the Holy Scriptures cites different points of view on the composition of the firmament of heaven: it can be like smoke (like smoke), have the structure of frozen water (like water), or consist of a special substance – ether (fifth, or maybe four things).

However, in addition to the two levels of heaven, John names another sphere located below the firmament and designated by the Greek term "uranos": ^{[23, p. 65]}. Translated from Greek, Oὐρανός means ‘heaven’, but in Greek mythology, uranos was a celestial space inhabited by the gods.

In the cosmological concept of John of Damascus, the Earth was located in the center of the universe at an equidistant distance from the celestial sphere. In turn, the celestial space had a spherical shape (the sky is the sky) and moved in a circle (the circle is the word heaven is coming).

Along with the interpretations of the three types of heaven in the texts of Damascene, one can find arguments about the existence of seven belts of aboveground space on which the planets were located: ^{[23, p. 63]}. The author of the treatise presents his own version of the origin of the name planet. As is known, the Greek word πλανήτης, literally meaning "wandering", is formed from the verb πλανάομαι "to wander" ^{[24, p. 78]}. John of Damascus argues that celestial bodies are called wandering because of the peculiarities of the trajectory of their movement, which is opposite to the movement of the sky: ^{[23, p. 63]}.

The translations of the works of John of Damascus that have come down to us do not allow us to build a clear concept of the structure of the firmament, characteristic of the philosophy of this Christian theologian. In different sections of the treatise "The Source of Knowledge", one can find arguments about three (or four) heavenly spheres, and about the seven belts of celestial space.

A unique monument of ancient Russian medieval literature is the "Palea Intelligentsia", created by an ancient Russian author in the 13th century. and has come down to us in the lists of the XIV–XVII centuries. According to the researchers, "Palea" was an ancient encyclopedia, which dealt with the problems of the structure of the Universe, the nature of man and the boundaries of his knowledge, as well as interpreted the existential and historical plots of the Old Testament. The author of the monument relied on the texts of Holy Scripture, apocryphal works, the works of the Church Fathers and texts of Christian church literature of the XI–XII centuries. Researcher of apocryphal texts V. V. Milkov notes: "A Russian literate person, generally speaking, learned biblical history not from the Bible, but mainly through the Palaea, in which the canonical element is balanced by the poetry of the abnegated books" ^{[25, p. 7]}. Thus, the analysis of Palea Tolkova makes it possible to identify the features of ideas about the structure of the world that are characteristic of the consciousness of a medieval Christian.

The beginning of the creation of the world is described in the text of the monument as follows: ^{[22, p. 168]}. The author emphasizes that angels appeared at the very beginning of the creation of the world and therefore they were eyewitnesses to all subsequent acts of creation. It is the mention of angels, which represent the initial creation of God and the heavens created together with heaven, that distinguishes the text of "Palea" from the canonical biblical story: ^{[22, p. 168]}.

Created on the first day of creation, the upper heaven and angels are immaterial entities that are incomprehensible to human perception. The only trait they possess is a dazzling brightness: ^{[22, p. 173]}. Both the angels and the sky of heaven are interpreted by the text of Palea Tolkova as the ultimate reality. However, for the author of Palea, as for any Christian thinker, the supreme unconditional spiritual essence is God the Creator.

Angels are able to command natural phenomena and weather conditions: ^{[22, p. 175]}. Angelic entities occupy an intermediate position in the heavenly hierarchy: on the one hand, they possess an immaterial nature and are close to God, and on the other, they can act in the material world, controlling the elements and weather phenomena.

Angelic forces have a strictly defined hierarchy and are grouped into groups and orders – ^{[22, p. 174]}. All subjects of the angelic hierarchy fulfill the will of the Almighty and are referred to in the text of the Palaea as ministering spirits: ^{[22, p. 175]}.

Based on the texts of the apocrypha, the author of Palea Tolkova contrasts the upper heaven, devoid of physical materiality, on the first day of creation with the firmament created on the second day: ^{[22, p. 176]}.

In the presented cosmological system, the firmament symbolizes the boundary separating the material physical world from the higher ideal world. Continuing the ideas outlined in other apocryphal texts, the author of "Palea Tolkova" compares the firmament with the overlap separating the parts of the building: ^{[22, p. 180]}. At the same time, the text indicates that the ice firmament has no support, but is held only by the power of the Creator.

The ice firmament divides the water element into the waters of the earth and the waters of heaven. In the space of waters located under the firmament ^{[22, p. 176]}. The waters spilled over the firmament should act as a universal cooler and cool the heat of the luminaries moving in the celestial space: ^{[22, p. 177]}.

The author of the monument enters into a polemic with supporters of the ideas of geocentrism and depicts the space of the Earth as flat and the firmament as stationary: ^{[22, p. 202]}. The alternation of day and night is explained by the circular movements of the Sun in the horizontal plane. During the day, the sun circumnavigates the entire terrestrial space, then disappears behind the mists in the northern part of the surface, and a night shadow falls on the Earth.

In the text of Palea, the author does not agree with those thinkers and theologians who preach the idea of a plurality of heaven, proving his version in the words of the prophet David: ^{[22, p. 180]}. The creator of the paleonic text argues that, firstly, in this context we are talking about the apostles; secondly, in Greek and Hebrew, plural forms can often be found in place of singular and dual forms (for example, the designation of the city of Athens). The Palea Tolkova, based on the texts of Holy Scripture, denies the multilevel interpretation of the firmament: ^{[22, p. 181]}. It should be noted that while denying the existence of several belts of aboveground space, the author of Palea speaks primarily about the structure of the higher heaven (heaven of heaven).

In the text of Palea Tolkova, one can find the development of John Damascene's ideas about the existence of planets and floating stars, each of which moves in its own celestial belt: ^{[22, p. 233]}.

An analysis of the text of Palea Tolkova suggests that the author was well acquainted with the works of supporters of various cosmological schools and on the pages of Palea he expounds the ideas of both planar-mosquito and geocentric interpretations of the world order. Despite the non-canonical interpretation of a number of biblical subjects and direct references to apocryphal texts, Palea the Sensible has always been considered a true book and identified with Holy Scripture: "The Russian literate learned biblical history not from the Bible, but mainly through Palea, in which, according to N. S. Tikhonravov's apt expression, "the canonical element it is balanced by the poetry of the abnegated books" ^{[25, p. 8]}.

Thus, the first ideas about the universe were limited to the knowledge of ancient man and encompassed primarily an accessible inhabited world inhabited by humans and other living beings. Observations of the air sphere located above habitable space eventually led to conclusions about the heterogeneity of the atmosphere. A person saw the Sun, Moon, and stars and realized that these physical objects were located in the sky. The firmament is finite, has the shape of a dome and touches the earth's surface along the horizon line.

The spread of the religious worldview leads to the inclusion in the model of the world order and representations of the "other" world, unknown, inspiring fear and awe. Most cosmological concepts place representatives of the ideal (immaterial) world on high ground or in the sky.

The habitat of the deities could not be located in the same plane with physical objects, although remote in space, but accessible to human eyes. It is no coincidence that both classical biblical and non-canonical texts contrast heaven, "which exists, not above, but visible," and heaven, "which does not exist, not visible, but above." This contrast seems to us to be fundamentally important for the reconstruction of the concept of "Heaven" in the religious consciousness of Orthodox Christians.

There are no unambiguous interpretations of the appearance of the airspace above the Earth's surface in non-canonical sources. In the monuments we have analyzed, the sky 1) is a plane that exists parallel to the earth's surface; 2) is described as a dome resting on the ground; 3) looks like a sphere that has no support and is held only by the power of divine design; 4) has a spherical shape and moves in a circle.

A fragment of the religious conceptual sphere of the X–XVII centuries, associated with the ideas of the heterogeneous structure of the firmament, could include metaphorical images from apocryphal texts known in Ancient Russia. Examples of such images are recorded in the work of Severian Gabalsky "Six speeches about the universe". The universe is likened to a building with two floors: the author compares the upper sky with the roof of the building, and the visible sky with the ceiling. In the same monument, the analogy of the firmament with the head is drawn: the sky of heaven is equated with the brain invisible to humans, and the "existing" sky is identified with the sky accessible to vision and located above the visible language.

The concept of "Heaven" in the minds of Christians of the Middle Ages also included the concept of a certain boundary (overlap) separating parts of the firmament and isolating the earthly world from the heavenly world. According to the biblical stories interpreted and supplemented in the apocrypha, the "upper" heaven, along with the angels, appeared on the first day of Creation. On the second day, God created a similar overlap in the lower visible sky, which divided the water element into the waters of the earth and the waters of heaven. The water masses were supposed to protect the earth's space from the heat of the heavenly bodies and reflect the light of celestial bodies to illuminate the earth's surface. According to medieval authors, the boundary substance had the structure of solidified water ("ice thickening", "ice composition", "like crystal", "hardened by flowing waters"). The verbalizers of these representations were the linguistic units "firmament", "firmament of heaven", "condensation of ice". Characteristically, in some texts, these units could also denote the first level of the firmament accessible to human perception. Consequently, in the ancient Russian worldview of the X–XVII centuries, the first level of the sky could act as the very "solid" boundary that separated the material world from the higher ideal world.