Hermæ, in Greek antiquities, quadrangular pillars, broader above than at the base, surmounted by a head or bust, so called either because the head of Hermes was most common or from their etymological connection with the Greek word iipj.iara (blocks of stone), which originally had no reference to Hermes at all.

In the oldest times Hermes, like other divinities, was worshipped in the form of a heap of stones or of an amorphous block of wood or stone, which afterwards took the shape of a phallus, the symbol of productivity. The next step was the addition of a head to this phallic column which became quadrangular (the number four was sacred to Hermes, who was born on the fourth day of the month), with the significant indication of sex still prominent. In this shape the number of hermæs rapidly increased, especially those of Hermes, for which the distinctive name of Hermhermae has been suggested.

In Athens they were found at the corners of streets; before the gates and in the courtyards of houses, where they were worshipped by women as having the power to make them prolific; before the temples; in the gymnasia and palaestrae. On each side of the road leading from the Stoa Poikile to the Stoa Basilcios, rows of Hermae were set up in such numbers by the piety of private individuals or public corporations, that the Stoa Basilcios was called the Stoa of the Hermæ.

The function of Hermes as protector of the roads, of merchants and of commerce, explains the number of Hermae that served the purpose of signposts on the roads outside the city. It is stated in the pseudo-Platonic Hipparchus that the son of Peisistratus had set up marble pillars at suitable places on the roads leading from the different country districts to Athens, having the places connected with the roads inscribed on the one side in a hexameter verse, and on the other a pentameter containing a short proverb or moral precept for the edification of travellers.

Sometimes they bore inscriptions celebrating the valour of those who bad fought for their country. Just as it was customary for the passer-by to show respect to the rudest form of the god (the heap of stones) by contributing a stone to the heap or anointing it with oil, in like manner small offerings, generally of dried figs, were deposited near the Hermæ, to appease the hunger of the necessitous wayfarer. Garlands of flowers were also suspended on the two arm-like tenons projecting from either side of the column at the top. These pillars were also used to mark the frontier boundaries or the limits of different estates.

The great respect attaching to them is shown by the excitement caused in Athens by the Mutilation of the Hermae just before the departure of the Sicilian expedition (May 415 BC). They formed the object of a special industry, the makers of them being called Hermoglyphi. The surmounting heads were not, however, confined to those of Hermes; those of other gods and heroes, and even of distinguished mortals, were of frequent occurrence. In this case a compound was formed: Hermathena (a herm of Athena), Hermares, Hermaphroditus, Hermanubis, Hermalcibiades, and so on. In the case of these compounds it is disputed whether they indicated a berm with the head of Athena, or with a Janus-like head of both Hermes and Athena, or a figure compounded of both deities.

The Romans not only borrowed the Hermes pillars for their deities which at an early period they assimilated to those of the Greeks (as Heracles Hercules) but also for the indigenous gods who preserved their individuality. Thus hermæ of Jupiter Terminalis (the hermæ being identified with the Roman termini) and of Silvanus occur. Under the empire, the function of the hermæ was rather architectural than religious. They were used to keep up the draperies in the interior of a house, and in the Circus Maximus they were used to support the barriers.

See the article with bibliography by Pierre Paris in Daremberg and Saglio's Dictionnaire des antiquités; for the mutilation of the Hermæ, Thucydides vi. 27; Andocides, De mysteriis; Grote, Hist. of Greece, ch. 58; H Weil, Etudes sur l'antiquité grecque (1900); Burolt, Griech. Gesch. (ed. 904), III. ii. p. 1287.