to maintain their supremacy until the battle of Leuetra. The confederation organized by Epaminondas had no real permanency, and until the Roman conquest the country was the scene of civil strife. The inhabitants were brave, hardv, and fond of fighting, so that they were in great demand as mercenaries. Among their shepherds and hunters the chief deities seem to have been Pan, Artemis, and Zeus, who was worshiped with human sacrifices on Mount Lycaeon till a comparatively late date. A form of pastoral poetry seems to have developed in Arcadia, which was at first crowded into the background by the Sicilian bucolics of Theocri- tus; "but later revived and influenced the Roman poets, wlicnce Arcadia has become a synonym for an idyllic pastoral country of peace, innocence, and simplicity.
ARCADIA. The title of various pastoral romances, suggested, doubtless, from the use of the word in Vergil's Eclogues, where it is spoken of as a realm of bucolic content. One of these romances is by Sannazaro, and appeared at the close of the Fifteenth Century; another is by Sir Philip Sidney, and was published in 1590; a" third is by Robert Greene, published in 1589; and a fourth by I.ope de Vega, in 1598. In 1640 Shirley wrote a dramatization of Sidney's tale.
ARCA'DIUS (c.377-408). The first Em-
peror of the East (A.D. 395-408). He was born
in Spain, and was the son of the Emperor Theo-
dosius, after whose death the Roman Empire
was divided into the Eastern and Western, Arca-
dius lived in Oriental state, and his dominion ex-
tended from the Adriatic Sea to the river Tigris,
and from Seythia to Ethiopia; but the real rulers
over this vast empire were, first, the Gaul Rufi-
nus, and afterwards the eunuch Eutropius. who
openly assumed the reins of government and the
command of the army, while Arcadius reposed in
luxurious indifference. In 399 Eutropius was
deposed by another usurper, Gainas, who, in his
turn, sooii fell a victim to his own ambition.
Afterwards Eudoxia, the wife of the Emperor,
assumed the supremacy. One really great man
adorned this period, the virtuous and eloquent
Chrj-sostom, who was persecuted by Eudoxia,
and through her influence exiled in 404, on ac-
count of his firm opposition to Arianism, which
the Empress herself favored. During the reign
of Arcadius his territories suffered by barbarian
incursions, earthquakes, and famine, but nothing
could disturb the indifference of the monarch.
He died, unlamented, A.D. 408. See Honorius.
ARCA'NI DIS'CIPLI'NA. See Disciplina Arcani.
ARCA'NUM, The Great. In the Middle Ages the Latin word arcanum. literally meaning secret, was used of any of the most valued preparations of alchemy (q.v.); but the name great arcanum was especially applied to the highest problems of the science, the discovery of such supposed great secrets of nature as the elixir of life or the philosopher's stone.
ARC DE TRIOMPHE DE L'ETOILE, -irk
dc tre'oNf de la'twal' (Fr., triumphal arch of
the star). The largest triumphal arch in the
world. It stands at the head of the Champs
Elysées, Paris, and was begun by Napoleon in
1806, and completed by Louis Philippe in 1836.
It was designed by Chalgrin, and is profusely ornamented with reliefs representing the Napoleonic victories, in commemoration of which it was erected. See Arch, Triumphal.
ARC DE TRIOMPHE DU CARROUSEL, iirk de tre'oNf di.i ka'roTT'zel' (Fr., triumphal arch of the tilting-match) . An arch built by Napoleon I. at Paris, in the square inclosed by the Tuileries and the Louvre, in commemoration of his victories during 1805-06. It is a smaller copy of the Arch of Constantine at Rome. See Arch, Triumphal.
AR'CE, .Span pron., iir'tha, Francisco
(1822-78). A California pioneer. He removed
to Alta California in 1833, and soon afterward
became secretary to General José Castro, then
commanding the Californian forces. In 1846,
while bringing a number of horses, supposed to
belong to the Californian Government, from So-
noma to the south, he was attacked (June 6)
by a company of Americans, supposedly insti-
gated by Captain John C. Fremont. The "Arce
affair" attracted widespread attention, and
marked the beginning of the Bear-Flag Revolt,
which resulted in the seizure of California by
the Americans.
AR'CESILA'US (Gk. 'ApKcalXaos.Arkesilaos)
(B.C. 316-241). A Greek philosopher, founder
of the Middle Academy. He was born at Pitane,
in Æolis; studied philosophy at Athens, first
under Theophrastus, the Peripatetic, and after-
wards under Grantor, the Academician, and
through the latter became acquainted with Pole-
mon and Crates, by whom, as well as by Grantor,
he was profoundly influenced in his philosophic
views. After the death of Grantor, he became
the head of the Academic school. Arcesilaus
marks a reaction against the dogmatism of the
Stoic school of philosophy, and an intended re-
currence to the method and attitude of Plato
and Socrates. He denied the Stoic doctrine of a
"convincing conception," which he affirmed to be,
from its very nature, unintelligible and contra-
dictory. He* also denied the certainty of intel-
lectual and sensuous knowledge, and recommend-
ed abstinence from all dogmatic judgments. In
practice, he maintained, we must act on grounds
of probability. Though Areesilaus confined his
activity to teaching by the Socratic method, and
wrote nothing, his influence on the future course
of philosophic thought was far-reaching. He
had clearness of thought, cutting wit, and readi-
ness of speech; his frank and generous disposi-
tion charmed his opponents as well as his dis-
ciples. Consult Zeller, Geschichte der griechischen Philosophie (Leipzig, 1893).
ARCH (Lat. arcus, anything curved, a bow, vault, arch). A term used in architecture to designate any curved form that spans an opening or recess. It may be decorative, as a floral arch; or constructional, as a stone or brick arch. It may be a detached structure, a memorial or triumphal arch; or it may be a part of a large building. A constructional arch may be a false arch, consisting of horizontal courses of masonry, each projecting over the one below it, the edges being chamfered to give the form of the arch without the carrying function; or it may be a true arch, with a keystone, as is usually the case, and may be of the greatest variety of shapes: a primitive triangle, formed of two slanting stones; a flat arch, with wedge-shaped voussoirs; a segmental arch, or very low arch, used often within walls, as a discharging arch, for strength;
