Yesterday, I received an e-mail from a frequent reader of Baring the Aegis who had seen my post on the small packages of the ancient statues and the post about taboos where nudity also plays an important role, and had begun to wonder about nudity at large in ancient Hellas, and specifically in a religious setting. They also wondered how I feel about nudity in modern Hellenismos. I would like to share my--slightly edited--reply with the readers of this blog, because others might be wondering about the ancient Hellenic attitude towards nakedness as well.
‘Naked’, gymnos, in the ancient Hellenic language has a double meaning: it means both nudity and ‘to go without chiton’, which complicates drawing conclusions from the written word. As such, most of the information gathered on this topic is based upon artwork, with a few exceptions. The ancient Hellenes had a very complicated view of nudity, and I don’t think I did that view justice back in 2012.
Before I get to the religious part, I feel I must look at every day life first. I want to start with ancient Hellenic clothing, which varied for males and females, although both only wore one or two rectangular pieces of cloth. Undergarments of any kind were unknown to the ancient Hellenes, and they were thus naked under them. Men throughout the whole of the ancient Hellenic time period wore either a chiton and himation, only a chiton, or only the himation. Socrates is famous for wearing only the latter, and so is Agesilaus, King of Sparta, and Phocion, who Plutarch joked about in ‘Phocion’, saying: 
“His countenance was so composed that scarcely was he ever seen by any Athenian either laughing or in tears. He was rarely known, so Duris has recorded, to appear in the public baths, or was observed with his hand exposed outside his cloak, when he wore one. Abroad, and in the camp, he was so hardy in going always thin clad and barefoot, except in a time of excessive and intolerable cold, that the soldiers used to say in merriment, that it was like to be a hard winter when Phocion wore his coat.“
There were very strict social rules about what was considered proper and improper for men when wearing only one of the two layers of clothing, and even when wearing both. Under no circumstances was the clothing to slide up above the knee during social affairs. It seems that any setting where nudity was not required--something we will come to below--nudity was forbidden quite strictly. Partial exposure like that was considered not only improper but irreverent, again, something I must explain later.
Women, whose style of clothing varied greatly throughout the ancient Hellenic time period, had to hold fast to different social rules concerning nudity. Statues and frescos show that in very archaic Knossos, for example, highly placed women wore garments which proudly exposed their breasts. When this style faded, others took its place. For their clothing, women in ancient Hellas often wore translucent materials, which left very little to the imagination. Many ancient writers, including Lucian, Petronius, and Seneca write about this, Seneca most tellingly:
“I see silk clothes, if they can be called clothes, which can protect neither the body nor the modesty.” [De Beneficiis, 7.9.5.]
It seems that women, while not nude, displayed a nakedness in the streets that was completely accepted. The social rules concerning these displays of the body depended on the intent of the nudity: either natural or erotic. Erotic nudity had no function in public, and was heavily frowned upon. Natural nakedness went accepted. For ancient Hellenic men, a woman’s girdle holding in place her dress was much more erotic than seeing her breasts through the thin fabric of her clothing.
Public nudity was not originally an Hellenic custom, but became one. From Thucydides’ ‘History of the Peloponnesian War’: 
“The Athenians were the first to lay aside their weapons, and to adopt an easier and more luxurious mode of life; indeed, it is only lately that their rich old men left off the luxury of wearing undergarments of linen, and fastening a knot of their hair with a tie of golden grasshoppers, a fashion which spread to their Ionian kindred and long prevailed among the old men there. On the contrary, a modest style of dressing, more in conformity with modern ideas, was first adopted by the Lacedaemonians, the rich doing their best to assimilate their way of life to that of the common people. They also set the example of contending naked, publicly stripping and anointing themselves with oil in their gymnastic exercises. Formerly, even in the Olympic contests, the athletes who contended wore belts across their middles; and it is but a few years since that the practice ceased. To this day among some of the barbarians, especially in Asia, when prizes for boxing and wrestling are offered, belts are worn by the combatants. And there are many other points in which a likeness might be shown between the life of the Hellenic world of old and the barbarian of to-day.“ [1.6]
Sports were a frequent platform of nudity: not only did males (and in Sparta and a few other choice city-states, females) who studied at the gymnasium practice sports and even their classes in the nude, there is evidence to support that the two genders did not hide their bodies from each other when women were permitted, and even that they wrestled each other while naked, showing that this type of nakedness was considered completely natural and accepted. Athenaeus records a Spartan custom of this, saying
“The fashion, too, of Sparta is much praised, I mean that of displaying their maidens naked to their guests; and in the island of Chios it is a beautiful sight to go to the gymnasia and the race-courses, and to see the young men wrestling naked with the maidens, who are also naked.” [13, 566e]

Sporting competitions were always in the nude. It seems that in antiquity, the athletes did wear something to hide their nether regions, but when this covering slipped off of a sprinter, and he tripped and fell to his death, any type of covering was forbidden. Married women, in most city states, (interestingly enough) were not allowed to watch sporting events, not even the major ones like to Olympics, although testimony Pindar (in Pythia) hints at the possibility that the Hellenic city-state of Cyrene allowed married women to watch. Maidens were more often allowed to view the games. Scholars pose that the distinction between maiden and married is made purely aesthetically: the ancient Hellenes valued beauty very much, and maidens were considered beautiful. They were virtuous and thus desirable. Married women were not to be seen as desirous; they were married.
Before I come to the religious part of this longwinded tale, I must address two more points: bathing and the ancient Hellenic practice to either be completely dressed, or completely naked. Bathing, in ancient Hellas, had quite an interesting set of social rules attached to it, especially before the Peloponnesian war. ’Baths’, when referred to in ancient texts, unless otherwise specified, nearly always alluded to bathing in hot or warm water, as many bathing house offered. at least until the previously mentioned war, bathing in warm water was  considered taboo for men. Warm water was for women; men were supposed to be a heartier breed and thus bathed in cold water. Aristophanes, in Clouds, forbids men from entering the baths, because they are baneful and effeminizing. From the writings of Plato, Demothenes, and Plutarch, we can see that this view was quite widespread (see Plutarch on Phocion above).
For my last point before I get to religion, it must be said that the ancient Hellenes felt no shame about their body, quite the opposite, in fact. The ancient Hellenes took great pride in beauty, and displayed their bodies proudly. Especially young males were considered pleasing, as described in my post about the small packages of statues. Sexual organs of both sexes were considered not only natural, but sacred. Aidos (Αἰδώς) is a term (and Goddess) interpreted often as ‘shame’ or ‘modesty’, and linked to he displaying of a person’s genitals, but the term can also mean ‘awe’ and ‘reverence’. The ancient Hellenes were well aware that their sexual organs--when brought together in an intimate setting--produced children. As such, these body parts were treated with an almost religious reverence as the mystical tools of propagation. These instruments produced life, something definitely awe inspiring. This is also how the phallus became a religious symbol; it represents the inexhaustible fruitfulness of human nature and the gratitude that came with this understanding.
Because sexual organs were considered somewhat sacred, covering them up--especially when otherwise naked--was considered impious, and so any socially acceptable situation where clothes were deemed cumbersome, unnecessary or impossible led to a state of complete nakedness. The ancient Hellenes took great pride in this fact, and to cover up one’s groin was considered barbaric. As Herodotos puts it so beautifully in his ‘Histories’:
“For among the Lydians, and indeed among the barbarians generally, it is reckoned a deep disgrace, even to a man, to be seen naked. ” [1, 7-11]
To conclude, nudity was generally accepted by the ancient Hellenes, although social rules had to be observed. Women rarely went completely uncovered in every day life, but displayed their bodies through their clothing. Men could cast off their clothing more readily. If either gender undressed, it was seen as irreverent to do so partly, and thus they appeared either fully clothed or naked. Partial nudity was frowned upon in almost all social settings, while full nudity was often accepted.
Now, as for religious worship: there are definitely some instances where complete nudity became required. In other festivals, I would assume--based on the above--that nudity was allowed, if the person went completely uncovered. A few examples of rituals where we know nudity was included:
  • The young maidens who ‘played the bear’ to Artemis at the Brauronia are depicted naked at various stages of the ritual
  • Athenaeus describes a 'naked-boy dance' in relation to the cult of Dionysos:  “The naked-boy-dance is like what is called the anapale among the ancients. For all the boys who dance it are naked, performing certain rhythmical movements and describing certain positions with the arms gently, so as to represent certain scenes in the wrestling-school during a wrestling-and-boxing match, but moving the feet in time to the music. Variations of it are the Oschophoric and the Bacchic, so that this dance also is traceable to the worship of Dionysus. Aristoxenus says that the ancients, practicing first the naked-boy-dance, proceeded into the pyrriche before entering the theatre.”
  • Arisophanes in ‘Clouds’ hints at this type of dance being performed during the Panathenaea as well: “But you, you teach the children of to-day to bundle themselves quickly into their clothes, and I am enraged when I see them at the Panathenaea forgetting Athene while they dance, and covering their tools with their bucklers.”
  • Stabo recorded the following example of public nudity at Acharaca in ancient Hellas:  “On the road between Tralles and Nysa is a village of the Nysaeans, not far from the city Acharaca, in which is the Plutonium, to which is attached a large grove, a temple of Pluto and Proserpine, and the Charonium, a cave which overhangs the grove, and possesses some singular physical properties. The sick, it is said, who have confidence in the cures performed by these deities, resort thither, and live in the village near the cave, among experienced priests, who sleep at night in the open air, on behoof of the sick, and direct the modes of cure by their dreams. The priests invoke the gods to cure the sick, and frequently take them into the cave, where, as in a den, they are placed to remain in quiet without food for several days. Sometimes the sick themselves observe their own dreams, but apply to these persons, in their character of priests and guardians of the mysteries, to interpret them, and to counsel what is to be done. To others the place is interdicted and fatal.
    An annual festival, to which there is a general resort, is celebrated at Acharaca, and at that time particularly are to be seen and heard those who frequent it, conversing about cures performed there. During this feast the young men of the gymnasium, and the ephebi, naked and anointed with oil, carry off a bull by stealth at midnight, and hurry it away into the cave. It is then let loose, and after proceeding a short distance falls down and expires.”
  • Vase paintings and frescos of Dionysios’ festivals often have men and women dancing naked.
  • I’m sure I have read somewhere that Aphrodite’s worship was also sometimes conducted naked, but I simply can not find the reference again.
Nudity was a part of ancient Hellenic religion, but not often a requirement. In most cases, clothes were cot considered a burden, so they remained on. In the case of Dionysian worship, clothes would hinder the ecstatic dances usually tied to them, so clothes were discarded. Functional nudity. That said, I have not found any references to festivals where public nudity was expressly forbidden.
I come from a Neo-Pagan background and was quite accustomed to performing rituals in the nude. It was a big shift to go to clothed ritual for me, but it does seem fitting somehow. The ancient Hellenic viewpoint of functional nudity seems practical and a good standard to uphold. That said, I am not against nudity in Hellenic ritual at all, if agreed upon by all participants and the occasion warrants it.
If you have a question for me, please, do not hesitate to contact me at the gmail address 'baring.the.aegis'.