2דֶּרֶךְ הָאֵשׁ וְהָרוּחַ לִהְיוֹת מַהֲלָכָם מִמַּטָּה מִטַּבּוּר הָאָרֶץ לְמַעְלָה כְּלַפֵּי הָרָקִיעַ. וְדֶרֶךְ הַמַּיִם וְהָאָרֶץ לִהְיוֹת מַהֲלָכָם מִתַּחַת הָרָקִיעַ לְמַטָּה עַד לָאֶמְצַע. שֶׁאֶמְצַע הָרָקִיעַ הוּא הַמַּטָּה שֶׁאֵין לְמַטָּה מִמֶּנּוּ. וְאֵין הִלּוּכָם לֹא בְּדַעְתָּם וְלֹא בְּחֶפְצָם אֶלָּא מִנְהָג שֶׁנִּקְבַּע בָּהֶן וְטֶבַע שֶׁנִּטְבַּע בָּהֶן. טֶבַע הָאֵשׁ חַם וְיָבֵשׁ וְהוּא קַל מִכֻּלָּם. וְהָרוּחַ חַם וְלַח. וְהַמַּיִם קָרִים וְלַחִים. וְהָאָרֶץ יְבֵשָׁה וְקָרָה. וְהִיא כְּבֵדָה מִכֻּלָּם וְהַמַּיִם קַלִּים מִמֶּנָּה לְפִיכָךְ נִמְצָאִים לְמַעְלָה עַל הָאָרֶץ. וְהָרוּחַ קַל מִן הַמַּיִם לְפִיכָךְ הוּא מְרַחֵף עַל פְּנֵי הַמַּיִם. וְהָאֵשׁ קַל מִן הָרוּחַ. וּמִפְּנֵי שֶׁהֵם יְסוֹדוֹת לְכָל גּוּפִים שֶׁתַּחַת הָרָקִיעַ יִמָּצֵא כָּל גּוּף וְגוּף מֵאָדָם וּבְהֵמָה וְחַיָּה וְעוֹף וְדַג וְצֶמַח וּמַתֶּכֶת וְאֶבֶן גָּלְמוֹ מְחֻבָּר מֵאֵשׁ וְרוּחַ וּמַיִם וְעָפָר. וְאַרְבַּעְתָּן יִתְעָרְבוּ בְּיַחַד וְיִשְׁתַּנּוּ כָּל אֶחָד מֵהֶם בְּעֵת הָעֵרוּב עַד שֶׁיִּמָּצֵא הַמְחֻבָּר מֵאַרְבַּעְתָּן אֵינוֹ דּוֹמֶה לְאֶחָד מֵהֶן כְּשֶׁהוּא לְבַדּוֹ. וְאֵין בַּמְעֹרָב מֵהֶן אֲפִלּוּ חֵלֶק אֶחָד שֶׁהוּא אֵשׁ בִּפְנֵי עַצְמוֹ אוֹ מַיִם בִּפְנֵי עַצְמָן אוֹ אֶרֶץ בִּפְנֵי עַצְמָהּ אוֹ רוּחַ בִּפְנֵי עַצְמָהּ אֶלָּא הַכּל נִשְׁתַּנּוּ וְנַעֲשׂוּ גּוּף אֶחָד. וְכָל גּוּף וְגוּף הַמְחֻבָּר מֵאַרְבַּעְתָּן יִמָּצֵא בּוֹ קֹר וְחֹם לַח וְיָבֵשׁ כְּאֶחָד. אֲבָל יֵשׁ מֵהֶם גּוּפִים שֶׁיִּהְיֶה בָּהֶם חָזְקָה מִיסוֹד הָאֵשׁ כְּמוֹ בַּעֲלֵי נֶפֶשׁ חַיָּה. לְפִיכָךְ יֵרָאֶה בָּהֶם הַחֹם יָתֵר. וְיֵשׁ מֵהֶן גּוּפִין שֶׁיִּהְיֶה בָּהֶן חָזְקָה מִיסוֹד הָאָרֶץ כְּמוֹ הָאֲבָנִים. לְפִיכָךְ יֵרָאֶה בָּהֶם הַיֹּבֶשׁ הַרְבֵּה. וְיֵשׁ מֵהֶן גּוּפִין שֶׁיִּהְיֶה בָּהֶן חָזְקָה מִיסוֹד הַמַּיִם. לְפִיכָךְ יֵרָאֶה בָּהֶם הַלַּח יָתֵר. וְעַל הַדֶּרֶךְ הַזֶּה יִמָּצֵא גּוּף חַם יֶתֶר מִגּוּף אַחֵר חַם. וְגוּף יָבֵשׁ יֶתֶר מִגּוּף אַחֵר יָבֵשׁ. וְכֵן יִמָּצְאוּ גּוּפִים שֶׁיֵּרָאֶה בָּהֶן הַקֹּר בִּלְבַד. וְגוּפִים יֵרָאֶה בָּהֶן הַלַּח בִּלְבַד. וְגוּפִים יֵרָאֶה בָּהֶן הַקֹּר וְהַיֹּבֶשׁ כְּאֶחָד בְּשָׁוֶה. אוֹ הַקֹּר וְהַלַּח כְּאֶחָד בְּשָׁוֶה. אוֹ הַחֹם וְהַיֹּבֶשׁ כְּאֶחָד בְּשָׁוֶה. אוֹ הַחֹם וְהַלַּח כְּאֶחָד בְּשָׁוֶה. לְפִי רֹב הַיְסוֹד שֶׁהָיָה בְּעִקַּר הַתַּעֲרֹבֶת יֵרָאֶה מַעֲשֵׂה אוֹתוֹ הַיְסוֹד וְטִבְעוֹ בַּגּוּף הַמְעֹרָב:
The tendency of fire and wind is to ascend upwards from the depths of the earth toward the sky. The tendency of water and earth is to descend from the sky to the midpoint of the sky, [i.e., the center of the Earth,] for the midpoint of the sky is the lowest point, below which nothing is lower. These tendencies are not a conscious matter, nor are they willful. Rather, it is a pattern affixed within them and a nature they were given. The natural characteristics of fire are that it is warm and dry. It is the lightest of all [these fundamental elements]. Wind is warm and moist. Water is cold and moist, and earth is dry and cold. It is the heaviest of all [these fundamental elements]. Water is lighter than earth. Therefore, it is found above it. Wind is lighter than water. Therefore, it hovers above it. Fire is even lighter than wind. Since these are the fundamental [elements] for all the bodies below the sky, the matter of every single body - man, animal, beast, fowl, fish, plant, metal, and stone - is a combination of fire, wind, water, and earth. [In the process of] the combination of these four, each one of them changes while they are being combined. Thus, the combination of the four [fundamental elements] does not resemble any one of the [elements] as it exists alone. [Similarly,] in any combination of them, there cannot be found even one portion of fire as it exists alone, wind as it exists alone, water as it exists alone, nor earth as it exists alone. Rather, they have all changed and become a single body. Each and every body which is a combination of these four [fundamental elements] will have a combination of cold and warmth, moistness and dryness. There are some bodies which have a more powerful [concentration] of the fundamental [element] of fire - for example, creatures with living souls. Accordingly, they have a higher temperature. [Conversely,] there are some bodies with a more powerful concentration of the element of earth - for example, the stones. Accordingly, they are very dry. Similarly, some of them have bodies with a greater concentration of the element of water. Accordingly, they are moist. In this manner, one may find one body which is warmer than another body, which is itself warm, and one body drier than another body, which is itself dry. Similarly, there are bodies in which cold alone is noticeable, and other bodies in which moistness alone is noticeable. In some bodies, cold and dryness are equally noticeable; in others, cold and moistness are equally noticeable; in others, warmth and dryness are equally noticeable; and in others, warmth and moistness are equally noticeable. According to the predominance of the element that is found in the essential combination, the inclination and nature of that element will be expressed in the body [resulting from] a mixture [of all the elements].