Chapter 25: The Sun

On the sun’s substance, size, shape, turnings, eclipse, signs, and motion.⁷⁴³

1a ⟨Aëtius⟩: Xenophanes

Xenophanes held that the sun consists of clouds set ablaze. An eclipse occurs when it is extinguished; another sun comes into being again at sunrise. He also recorded an eclipse of the sun lasting a whole month, and another that was complete, so that day appeared as night.⁷⁴⁴

1b ⟨Aëtius⟩: Theophrastus’ report

Theophrastus wrote in his Physical Studies that the sun consists of small particles of fire which gather together ⟨from⟩ moist exhalation and, by their gathering, make up the sun.⁷⁴⁵

1c ⟨Aëtius⟩: Anaximander’s fiery wheel

Anaximander held that there is a circle twenty-eight times the size of the earth, resembling a chariot wheel. Its rim is hollow and full of fire, which it reveals at one point through an opening, as through a bellows nozzle.⁷⁴⁶ The sun itself is equal in size to the earth; the circle from which its fiery breath comes, and by which it is carried around, has the size already stated. An eclipse occurs when the opening through which the fire breathes out is closed.

1d ⟨Aëtius⟩: Anaximenes

Anaximenes declared that the sun is fiery. The heavenly bodies make their turnings when pushed away by air that has become dense and resistant. The sun is flat in shape.⁷⁴⁷

1e ⟨Aëtius⟩: Parmenides and Metrodorus

Parmenides and Metrodorus held that the sun is fiery.

1f ⟨Aëtius⟩: Antiphon

Antiphon held that the sun is fire feeding upon the moist air around the earth. It rises and sets as it continually leaves behind the air being burned and takes hold again of air becoming moist.⁷⁴⁸

1g ⟨Aëtius⟩: Heraclitus and Hecataeus

Heraclitus and Hecataeus held that the sun is an intelligent kindling of fire arising from the sea. Its shape is that of a bowl, slightly convex. An eclipse occurs when the bowl turns, bringing its hollow side upward and its convex side downward toward our sight. Its size is “the breadth of a human foot.”⁷⁴⁹

1h ⟨Aëtius⟩: Alcmaeon

Alcmaeon held that the sun is flat.

1i ⟨Aëtius⟩: The Pythagoreans

The Pythagoreans held that the sun is spherical. An eclipse occurs when the moon passes in front of it.⁷⁵⁰

2 Porphyry, from On Images

From Porphyry’s On Images.

Just as the sun too follows a course contrary to the revolving heavens, itself moving from west to east.⁷⁵¹

3a ⟨Aëtius⟩: Anaxagoras

Anaxagoras held that the sun is a glowing mass or a red-hot stone. Its turning occurs through the counterthrust of the air in the north, which the sun itself compresses and strengthens by making it dense.⁷⁵²

3b ⟨Aëtius⟩: Thales

Thales held that the sun is earthy. It is eclipsed when the moon, which is earthy in nature, passes directly in front of it. This can be seen by means of a mirror placed beneath the disk.⁷⁵³

3c ⟨Aëtius⟩: Diogenes

Diogenes held that the sun is like pumice, with rays from the aether becoming lodged in it. It is extinguished by the cold that confronts its heat.⁷⁵⁴

3d ⟨Aëtius⟩: Philolaus’ reflected sunlight

Philolaus the Pythagorean held that the sun is glass-like. It receives the radiance of the fire in the world and filters both light and warmth through to us. Thus there are, in a sense, two suns: the fiery substance in heaven, and the fire-like appearance derived from it through the mirror-like body. Unless one also counts a third: the radiance scattered toward us by reflection from the mirror.⁷⁵⁵

3e ⟨Aëtius⟩: Empedocles’ two suns

Empedocles held that there are two suns. The original is fire in one hemisphere of the world, filling that hemisphere and always stationed directly opposite its own reflection. The visible sun is a reflection in the other hemisphere, which is filled with air mixed with heat. This reflection is produced from the rounded earth onto the crystal-like sun, and is carried around with the movement of the fiery hemisphere. To put it briefly, the sun is a reflection of the fire surrounding the earth.⁷⁵⁶

3e ⟨Aëtius⟩: Turnings, size, and eclipse

Its turning occurs because the sphere enclosing it and the tropic circles prevent it from continuing straight onward indefinitely. The sun formed by reflection is equal in size to the earth. An eclipse occurs when the moon passes in front of it.⁷⁵⁷

3f ⟨Aëtius⟩: Epicurus

Epicurus says that the sun is a compact earthy mass, lit by fire through its pores as in pumice or a sponge. It is as large as it appears, or a little larger or smaller.⁷⁵⁸

3g ⟨Aëtius⟩: Parmenides

Parmenides held that the sun and moon separated out of the Milky Way: the sun from the thinner mixture, which is hot, and the moon from the denser mixture, which is cold.⁷⁵⁹

3h ⟨Aëtius⟩: Democritus

Democritus held that the sun is a glowing mass or a red-hot stone. Its turning results from the whirling motion that carries it around.

3i ⟨Aëtius⟩: Cleanthes and nourishment

Cleanthes held that the sun is an intelligent kindling of fire arising from the sea. As for its turnings, they say that these follow the extent of the nourishment beneath it. Ocean is ... whose exhalation it feeds upon.⁷⁶⁰

3i ⟨Aëtius⟩: A spiral course

The sun is carried along while moving in a spiral within the sphere, from the equator toward both north and south, which are the limits of the spiral. Others say that it advances in a straight direction, tracing its spiral around a cylinder rather than a sphere.⁷⁶¹

3k ⟨Aëtius⟩: Aristarchus

Aristarchus makes the sun stationary along with the fixed stars, while the earth moves around the solar circle and is put in shadow according to its inclinations.⁷⁶²

3k ⟨Aëtius⟩: Xenophanes’ many suns

Xenophanes held that there are many suns and moons corresponding to the earth’s regions, divisions, and zones. At a certain time the disk falls into some division of the earth uninhabited by us, and thus, as though stepping into emptiness, presents the appearance of an eclipse. He also held that the sun proceeds onward without limit, but appears to move in a circle because of its distance.⁷⁶³