Pt1 The Celestial Spheres According to Maimonides’ Mishneh Torah (Laws of Foundations of the Torah 3:1-9)

This is the first part of a two-part series.¹ The outline for the series is below.

Maimonides' (fl. late 12th century) cosmological account in Mishneh Torah (=MT), Laws of the Foundations of the Torah presents a medieval synthesis of classical Greek astronomy (largely based on Aristotle and Ptolemy) and Jewish theology. This series of sections (slightly less than a chapter) outlines his understanding of the celestial spheres, combining astronomical observations with theological understandings about the nature of heavenly bodies.

Maimonides describes a geocentric universe of nine concentric spheres, with Earth at the center. The first seven spheres contain the seven classical planets (including the sun and moon), the eighth holds the fixed stars, and the ninth is the daily-rotating outer sphere. Maimonides details how these spheres are crystalline in nature, allowing visibility through multiple layers, and refers to the fact that complex motions are required to account for observed planetary movements.

What makes this account particularly interesting is how Maimonides integrates Greek astronomical tradition with theological claims. While providing detailed physical descriptions - including specific size comparisons between celestial bodies - he also attributes consciousness and divine worship to these spheres, positioning them in a hierarchy of intelligence between humans and angels.²

Outline

1. The Nine Celestial Spheres

2. Structure and Movement of the Celestial Spheres

3. Properties of the Celestial Spheres

4. Spherical Nature of the Cosmos

5. Counting the Spheres

6. Division of the Ninth Sphere Into the Zodiac Constellations

7. Star Movements, Sizes, and Ancient Divisions

   1. Part 1

   2. Part 2

8. Consciousness of Spheres and Celestial Bodies

9. Appendix #1 - The Angelic Hierarchy (MT, Laws of Foundations of the Torah, 2:7)

10. Appendix #2 - The Complexity of Lunar Calculations and the Universality of Astronomical Truth (MT, Laws of Sanctification of the New Month, 17:23-24)

    1. The Challenge of Lunar Calculations

    2. Sources of Astronomical Wisdom

    3. Reliance on Evidence, Not Authority

The Passage

Mishneh_Torah%2C_Foundations_of_the_Torah.3.1-9

The Nine Celestial Spheres

The heavens are composed of nine (celestial) spheres.³ These celestial spheres are also referred to as Heaven (שמים), Rakia (רקיע), Zevul (זבול), and Aravot (ערבות).⁴

Each of the nine spheres is named by the celestial body in it:⁵

1. Moon (ירח)

2. Mercury (כוכב)

3. Venus (נגה)

4. Sun (חמה)

5. Mars (מאדים)

6. Jupiter (צדק)

7. Saturn (שבתי)

8. Visible stars (כוכבים)

9. The ninth sphere rotates daily from east to west, encompassing and encircling everything.⁶

Though the planets and stars seem to all share one sphere, that’s simply due to the transparency of the spheres, which are “pure and refined like glass or sapphire” (טהורים וזכים כזכוכית וכספיר).

הגלגלים הם הנקראים שמים, ורקיע, וזבול, וערבות.

והם תשעה גלגלים.

1. גלגל הקרוב ממנו -- הוא גלגל הירח.

2. והשני שלמעלה ממנו -- הוא גלגל שבו הכוכב הנקרא כוכב.

3. וגלגל שלישי שלמעלה ממנו -- שבו נגה.

4. וגלגל רביעי -- שבו חמה.

5. וגלגל חמישי -- שבו מאדים.

6. וגלגל ששי -- שבו כוכב צדק.

7. וגלגל שביעי -- שבו שבתי.

8. וגלגל שמיני -- שבו שאר כל הכוכבים שנראים ברקיע.

9. וגלגל תשיעי -- הוא גלגל החוזר בכל יום מן המזרח למערב, והוא המקיף ומסבב את הכל.

וזה שתראה כל הכוכבים כאלו הם כלם בגלגל אחד

ואף על פי שיש בהן זה למעלה מזה,

מפני שהגלגלים טהורים וזכים כזכוכית וכספיר

לפיכך נראים הכוכבים שבגלגל השמיני מתחת גלגל הראשון

The spheres are called the heavens, the firmament, the habitation, the skies.

There are nine spheres:

1. The closest sphere is the sphere of the moon.

2. The second sphere, which is above it, is the sphere which contains the planet Kochav.

3. The third sphere, which is above it, contains [the planet] Nogah.

4. The fourth sphere contains the sun.

5. The fifth sphere contains [the planet] Ma'dim.

6. The sixth sphere contains the planet Tzedek.

7. The seventh sphere contains [the planet] Shabbtai.

8. The eighth sphere contains all the stars which are seen in the sky.

9. The ninth sphere is the sphere which revolves each day from the east to the west. It surrounds and encompasses everything.

The planets and stars all appear to be in one sphere,

even though one is higher than another.

This is because the spheres are pure and refined like glass or sapphire.

Therefore, the stars in the eighth sphere appear lower than the first sphere.

Structure and Movement of the Celestial Spheres

Each of the eight planetary spheres consists of multiple layers, like an onion.

These spheres rotate in various directions—some west to east and others east to west, like the ninth sphere.⁷

There is no empty space between the spheres.

כל גלגל וגלגל משמונה הגלגלים שבהן הכוכבים נחלק לגלגלים הרבה, זה למעלה מזה, כמו גלדי בצלים.

מהן גלגלים סובבים ממערב למזרח.

ומהן סובבים ממזרח למערב, כמו הגלגל התשיעי -- החוזר ממזרח למערב.

וכלן אין ביניהם מקום פנוי

Each of the eight spheres which contain the planets and stars are themselves divided into many spheres, one above the other like the layers of an onion.

Some of these spheres revolve from the west to the east,

and some revolve from the east to the west, such as the ninth sphere, which revolves from the east to the west.

There is no empty space between any of them.

Properties of the Celestial Spheres

The spheres lack physical qualities such as weight, taste, or color.⁸

Their blue (תכלת) appearance is an optical effect (מראית העין) caused by atmospheric⁹ height.

These phenomena¹⁰ (weight, taste, color) are restricted to matter (גופות) below the spheres.¹¹

כל הגלגלים אינן

1. לא קלים

2. ולא כבדים

3. ואין להם

   1. לא עין אדם

   2. ולא עין שחר

   3. ולא שאר עינות.

וזה שאנו רואין אותם כעין התכלת,

למראית העין בלבד הוא, לפי גבה האויר.

וכן אין להם לא טעם ולא ריח

לפי שאין אלו המארעין מצויין אלא בגופות שלמטה מהן

None of the spheres are light or heavy. They are neither red, black, nor any other color.

Though we see them as blue,

this is only our perception, because of the height of the atmosphere.

Similarly, they have neither taste nor smell,

because these phenomena are present only in matter lower than they.

Spherical Nature of the Cosmos

The celestial spheres (גלגלים) are spherical,¹² encircling the Earth, which is suspended (תלויה) at their center.

Some planets have smaller spheres affixed to them that do not encircle (מקיפין) the Earth but are embedded within the larger spheres.¹³

כל הגלגלים האלו המקיפין את העולם,

הן עגלין ככדור

והארץ תלויה באמצע.

ויש למקצת מן הכוכבים גלגלים קטנים שהן קבועים בהן

ואין אותם הגלגלים מקיפין את הארץ

אלא גלגל קטן שאינו מקיף, קבוע בגלגל הגדול המקיף

All these [nine] spheres which surround the world

are spherical like a ball,

and the Earth is suspended in their midst.

Some of the planets have small spheres fixed [around] them.

These spheres do not surround the Earth.

Rather, a small sphere which does not surround the Earth is fixed within a large sphere which does.

Counting the Spheres

Eighteen spheres encompass the Earth, while eight smaller, non-encompassing spheres exist.

Knowledge of celestial motions and distances enables the calculation of their paths and orbits:

“From the motion (מהלך) of the planets,

their daily and hourly rotations (סביבתן),

their inclination (נטיתן) from south to north and from north to south,

their height above the earth and their proximity,

one can discern the number of all these spheres, their movement patterns, and the manner of their orbit (הקפתן).”

This forms the basis of astronomical science;¹⁴ about which many books were written by Greek scholars (חכמי יון).

מספר כל הגלגלים המקיפין את כל העולם -- שמונה עשר.

ומספר הגלגלים הקטנים שאינן מקיפין -- שמונה.

וממהלך הכוכבים,

וידיעת שעור סביבתן בכל יום ובכל שעה

ומנטיתן מרוח דרום לרוח צפון, ומרוח צפון לרוח דרום

ומגבהן מעל הארץ, וקריבתן

יודע מספר כל אלו הגלגלים, וצורת הליכתן, ודרך הקפתן.

וזו היא חכמת חשבון תקופות ומזלות.

וספרים רבים חברו בהן חכמי יון

The total number of spheres which surround the Earth entirely is eighteen,

and the number of smaller spheres which do not surround [the world] is eight.

From the movement of the planets

and the knowledge of the extent of their revolution each day and each moment,

their position either northward or southward,

and their distance above the Earth and closeness to it,

[it is possible to] know the number of all these spheres, the manner in which they proceed, and the nature of their orbit.

This is the science of calculating the seasons and astronomy.

Many books about these subjects were written by the wise men of Greece.

1. See also my previous pieces on other works by Maimonides:

• “On an important digital layout of Maimonides’ Sefer HaMitzvot”

• “On an important digital layout of Maimonides’ Lists of Tannaim in his Introduction to his Commentary to the Mishnah”

2. See also, elsewhere in Maimonides' Mishneh Torah:

• The Calculations of the Hebrew Calendar (MT, Laws of Sanctification of the New Month, Chapters 6-17), where Maimonides discusses the calculations underlying the Hebrew calendar, based on Greek astronomy. See my appendix where I quote Maimonides’ conclusion to those chapters, where he explicitly writes that his sources were Greek.

• The Dynamics of the Four Elements: Composition, Characteristics, and Cyclical Transformations (MT, Laws of Foundations of the Torah, 3:10-4:5a.

All these extended non-legal sections are unusual for Mishneh Torah, which is primarlily focused on legal halachic codification (even more so than the Talmud is, compare my recent “Popular Myths About the Talmud: A Critical Examination“, that the Talmud’s content is roughly one-third non-legal.)

3. גלגלים - originally meaning: “wheels”. The word came to have the technical sense of “celestial spheres” in medieval Hebrew literature.

4. These are three of the names of the Seaven Heavens according to the Talmud, specifically Heavens # 2,4,7. See my recent piece “Pt2 Talmudic Cosmology (Ma'aseh Bereshit): Earth's Foundations, the Seven Heavens, and Cosmic Dimensions (Chagigah 12b-13a)“, section “The Seven Heavens (Chagigah 12b, sections #5-7,10-14)“.

5. These seven classical planets, with the same Hebrew names, are listed in the Talmud, see my piece “Pt2 Astrological Destinies in the Talmud: Influence of Birth Timings on Character (Shabbat 156a)”, section “Constellations and Birth Influences, Influences of planets”.

6. This ninth, outermost sphere is called Primum Mobile in the classical Greek tradition of astronomy; see also later sections on this sphere.

7. See Deferent and epicycle - Wikipedia:

In the Hipparchian, Ptolemaic, and Copernican systems of astronomy, the epicycle (from Ancient Greek […] epíkuklos 'upon the circle', meaning "circle moving on another circle") was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets.

In particular it explained the apparent retrograde motion of the five planets known at the time. Secondarily, it also explained changes in the apparent distances of the planets from the Earth.

8. The word used for “color” here is ayin - עין . For this sense of the word, which is biblical, see Hebrew Wiktionary, definition #2 (“לשון המקרא: מה שרואים, מראה. בדר"כ צִבְעוֹ של הדבר.“).

9. אויר - literally: “air". (The word literally means "air”, but might mean " aether” here.)

10. מארעין - originally: “happenings”. The word came to have the technical sense of “accident", in the philosophical sense, in medieval Hebrew literature.

See Wikipedia, “Accident (philosophy)“:

An accident […] in metaphysics and philosophy, is a property that the entity or substance has contingently, without which the substance can still retain its identity. An accident does not affect its essence, according to many philosophers.

It does not mean an "accident" as used in common speech, a chance incident, normally harmful.

Examples of accidents are color, taste, movement, and stagnation.

Accident is contrasted with essence: a designation for the property or set of properties that make an entity or substance what it fundamentally is, and which it has by necessity, and without which it loses its identity.

Aristotle made a distinction between the essential and accidental properties of a thing.

11. I.e. in the sublunary sphere; on Earth, in the four classical elements of the Greek scientific tradition. On the four classical elements and their dynamic, see at length in MT, Laws of Foundations of the Torah, 3:10-4:5a.

12. עגלין ככדור - literally: “round like a ball”.

13. As mentioned earlier, regarding deferent and epicycle.

14. חכמת חשבון תקופות ומזלות - literally: “The wisdom of calculating seasons and zodiac signs (=the twelve constellations)”.