Plutarch's dialogue "On the Face in the Moon": friends debate why the moon shows a face, whether it is inhabited, and end with a myth of souls dissolving into it.
On the Face Which Appears in the Orb of the Moon is a dialogue in Plutarch's Moralia in which a group of speakers - including Lamprias, Apollonides, and Sulla - work through the puzzle of the dark markings visible on the moon's surface. The conversation opens by dismissing simple explanations, such as the idea that the face is merely an optical dazzling of weak eyesight, and moves through a series of named theories: Clearchus's notion that the marks are a mirrored reflection of Earth's outer sea, and various physical accounts involving light, shadow, and reflected sunlight from mountains and hollows on the lunar body.
The middle of the dialogue turns to a broader physical and cosmological argument about whether the moon is earthy and heavy like our world, or fiery like the stars, and why bodies occupy the places they do in the cosmos at all. Speakers reject purely mechanical accounts of heaviness and lightness, arguing instead that each part of the cosmos - fire here, earth there, the sun as a heart, the moon as a liver or intermediary organ - is arranged by reason for what is useful and fitting, not simply flung into place by natural weight. This section engages Aristotelian and Stoic physics, Empedocles, and earlier astronomers such as Metrodorus of Chios, testing their claims against direct observation of the moon's surface and position between earth and the fixed stars.
The dialogue closes with an extended myth, attributed to a stranger's report, describing the moon and sun as way-stations for the soul after death: the earth receives and gives back the body, the moon receives and returns the soul, and the sun receives and returns the intellect. Good, philosophic souls dissolve quickly and peacefully into the moon, while restless or passionate souls - the mythic Tityoi and Typhon among them - are held in turmoil until the moon calms and eventually reabsorbs them. This closing image gives the work lasting interest: it fuses Greek astronomy, physics, and eschatology into one coherent picture of a moon that is at once a real celestial body and a psychological resting place for the dead.
“so too in inquiries that are hard to see through and hard to resolve, when the common, reputable, and familiar accounts fail to persuade, it is necessary to try the stranger ones, and not to despise them”
— De Faciae Quae In Orbe Lunae Apparet · read this chapter →
“the sun sharp-darting, and the moon mild”
— De Faciae Quae In Orbe Lunae Apparet · read this chapter →
“the man says that the so-called face in the moon consists of mirror-images and reflections of the great sea, appearing on the moon”
— De Faciae Quae In Orbe Lunae Apparet · read this chapter →
“The moon, lying between sun and earth like a liver, or some other soft inward organ, set between heart and belly, transmits the warmth from above to this region”
— De Faciae Quae In Orbe Lunae Apparet · read this chapter →
“the moon both receives and gives, and combines and divides”
— De Faciae Quae In Orbe Lunae Apparet · read this chapter →
It is a Moralia dialogue in which several speakers debate why the moon appears to have a face - the pattern of dark and light patches on its surface - working through and rejecting rival theories before turning to a cosmological argument about how the universe is ordered and closing with a myth about the afterlife of the soul.
The dialogue explores the moon's nature at length, discussing whether it is earthy or fiery and what role it plays between earth and sun, but its main interest is less in settling the question of lunar life than in explaining the visible markings and the moon's cosmic function as a way-station for souls.
Sulla relates a story, reportedly heard from a stranger, in which the earth receives and returns the body at death, the moon receives and returns the soul, and the sun receives and returns the intellect; virtuous souls dissolve into the moon peacefully, while restless souls like Typhon are held in turmoil until the moon eventually calms and reabsorbs them.
Clearchus is cited as holding that the face on the moon is a mirrored reflection of Earth's outer sea, with the moon's curved surface acting like a great polished mirror; the speakers find this theory ingenious but ultimately refute it because the sea's single continuous nature does not match the way the moon's bright and dark regions are divided into distinct, bounded patches.
He argues against the idea that heavy things simply fall and light things simply rise, instead comparing the cosmos to a living body in which each part - fire, earth, sun, moon - is placed where it is useful and fitting, governed by reason rather than raw physical necessity.
Moralia: Ad Principem Ineruditum · Moralia: Adversus Colotem · Moralia: Amatoriae Narrationes · Moralia: Amatorius · Moralia: An Recte Dictum Sit Latenter Esse Vivendum · Moralia: An Seni Respublica Gerenda Sit · Moralia: An Virtus Doceri Possit · Moralia: An Vitiositas Ad Infelicitatem Sufficia · Moralia: Animine An Corporis Affectiones Sint Piores · Moralia: Apophthegmata Laconica · Moralia: Aquane An Ignis Sit Utilior · Moralia: Bruta Animalia Ratione Uti