Progress in scientific research is due largely to provisional explanations which are constructed by imagination, but such hypotheses must be framed in relation to previously ascertained facts and in accordance with the principles of the particular science. In spite, however, of these broad practical considerations, imagination differs fundamentally from belief in that the latter involves “objective control of subjective activity” (Stout). The play of imagination, apart from the obvious limitations (e.g. of avoiding explicit self-contradiction), is conditioned only by the general trend of the mind at a given moment. Belief, on the other hand, is immediately related to practical activity: it is perfectly possible to imagine myself a millionaire, but unless I believe it I do not, therefore, act as such. Belief always endeavours to conform to objective conditions; though it is from one point of view subjective it is also objectively conditioned, whereas imagination as such is specifically free. The dividing line between imagination and belief varies widely in different stages of mental development. Thus a savage who is ill frames an ideal reconstruction of the causes of his illness, and attributes it to the hostile magic of an enemy. In ignorance of pathology he is satisfied with this explanation, and actually believes in it, whereas such a hypothesis in the mind of civilized man would be treated as a pure effort of imagination, or even as a hallucination. It follows that the distinction between imagination and belief depends in practice on knowledge, social environment, training and the like.
Although, however, the absence of objective restraint, i.e. a certain unreality, is characteristic of imagination, none the less it has great practical importance as a purely ideational activity. Its very freedom from objective limitation makes it a source of pleasure and pain. A person of vivid imagination suffers acutely from the imagination of perils besetting a friend. In fact in some cases the ideal construction is so “real” that specific physical manifestations occur, as though imagination had passed into belief or the events imagined were actually in progress.
IMĀM, an Arabic word, meaning “leader” or “guide” in
the sense of a “pattern whose example is followed, whether for
good or bad.” Thus it is applied to the Koran, to a builder’s
level and plumb-line, to a road, to a school-boy’s daily task,
to a written record. It is used in several of these, senses in the
Koran, but specifically several times of leaders and (ii. 118)
of Abraham, “Lo, I make thee a pattern for mankind.” Imām
thus became the name of the head of the Moslem community,
whose leadership and patternhood, as in the case of Mahomet
himself, is to be regarded as of the widest description. His
duty is to be the lieutenant, the Caliph (q.v.) of the Prophet,
to guard the faith and maintain the government of the state.
Round the origin and basis of his office all controversies as to
the Moslem state centre. The Sunnites hold that it is for men
to appoint and that the basis is obedience to the general usage
of the Moslem peoples from the earliest times. The necessity
for leaders has always been recognized, and a leader has always
been appointed. The basis is thus agreement in the technical
sense (see Mahommedan Law), not Koran nor tradition from
Mahomet nor analogy. The Shī’ites in general hold that the
appointment lies with God, through the Prophet or otherwise,
and that He always has appointed. The Khārijites theoretically
recognize no absolute need of an Imām; he is convenient and
allowable. The Motazilites held that reason, not agreement,
dictated the appointment. Another distinction between the
Sunnites and the Shī’ites is that the Sunnites regard the Imām
as liable to err, and to be obeyed even though he personally
sins, provided he maintains the ordinances of Islām. Effective
leadership is the essential point. But the Shī’ites believe that
the divinely appointed Imām is also divinely illumined and preserved
(ma‘ṣūm) from sin. The above is called the greater
Imāmate. The lesser Imāmate is the leadership in the Friday
prayers. This was originally performed by the Imām in the
first sense, who not only led in prayers but delivered a sermon
(khuṭba); but with the growth of the Moslem empire and the
retirement of the caliph from public life, it was necessarily given
over to a deputy—part of a gradual process of putting the
Imāmate or caliphate into commission. These deputy Imāms
are, in Turkey, ministers of the state, each in charge of his own
parish; they issue passports, &c., and perform the rites of circumcision,
marriage and burial. In Persia among Shī’ites their
position is more purely spiritual, and they are independent of
the state. A few of their leaders are called Mujtahids, i.e. capable
of giving an independent opinion on questions of religion and
canon law. A third use of the term Imām is as an honorary
title. It is thus applied to leading theologians, e.g. to Abū
Ḥanīfa, ash-Shāfi‘ī, Malik ibn Anas, Aḥmad ibn Ḥanbal (these
are called “the four Imāms”), Ghazāli.
See McG. de Slane’s transl. of Ibn Khaldūn’s Prolégomènes, i. 384 seq., 402 seq., 426 seq., 445; iii. 35, 58 seq.; Ostrorog’s transl. of Māwardī’s Ahkām i. 89 seq.; Haarbrücker’s transl. of Shahrastānī by index; Juynboll’s De Mohammedanische Wet, 316 seq.; Sell’s Faith of Islam, 95 seq.; Macdonald’s Development of Muslim Theology, 56 seq. (D. B. Ma.)
IMBECILE (through the French from Lat. imbecillus or imbecillis,
weak, feeble; of unknown origin), weak or feeble, particularly
in mind. The term “imbecility” is used conventionally of
a condition of mental degeneration less profound than “idiotcy”
(see Insanity).
IMBREX (Latin for “tile”), in architecture the term given to
the covering tile of the ancient roof: the plain tile is turned up on
each side and the imbrex covers the joint. In the simpler type of
roof the imbrex is semicircular, but in some of the Greek temples
it has vertical sides and an angular top. In the temple of Apollo
at Bassae, where the tiles were in Parian marble, the imbrex on
one side of the tile and the tile were worked in one piece out of the
solid marble.
IMBROS, a Turkish island in the Aegean, at the southern end
of the Thracian Chersonese peninsula. It forms with Samothrace,
about 17 m. distant, a caza (or canton) in the sanjak of Lemnos
and province of the Archipelago Isles. Herodotus (v. 26) mentions
it as an abode of the historic Pelasgians (q.v.). It was, like
Samothrace, a seat of the worship of the Cabeiri (q.v.). The
island is now the seat of a Greek bishopric. There is communication
with the mainland by occasional vessels. The island is of
great fertility—wheat, oats, barley, olives, sesame and valonia
being the principal products, in addition to a variety of fruits.
Pop. about 92,000, nearly all Turks.
IMERETIA, or Imeritia a district in Russian Transcaucasia,
extends from the left bank of the river Tskheniz-Tskhali to the
Suram range, which separates it from Georgia on the east, and is
bounded on the south by Akhaltsikh, and thus corresponds
roughly to the eastern part of the modern government of Kutais.
Anciently a part of Colchis, and included in Lazia during the
Roman empire, Imeretia was nominally under the dominion of
the Greek emperors. In the early part of the 6th century it
became the theatre of wars between the Byzantine emperor
Justinian and Chosroes, or Khosrau, king of Persia. Between
750 and 985 it was ruled by a dynasty (Apkhaz) of native princes,
but was devastated by hostile incursions, reviving only after it
became united to Georgia. It flourished until the reign of Queen
Thamar, but after her death (1212) the country became impoverished
through strife and internal dissensions. It was
reunited with Georgia from 1318 to 1346, and again in 1424.
But the union only lasted forty-five years; from 1469 until 1810
it was governed by a Bagratid dynasty, closely akin to that which
ruled over Georgia. In 1621 it made the earliest appeal to
Russia for aid; in 1650 it acknowledged Russian suzerainty and
in 1769 a Russian force expelled the Turks. In 1803 the
monarch declared himself a vassal of Russia, and in 1810 the
little kingdom was definitively annexed to that empire. (See
Georgia.)
IMIDAZOLES, or Glyoxalines, organic chemical compounds containing the ring system HN | CH = CH | . |
| | ||
CH = N |
Imidazole itself was first prepared by H. Debus (Ann. 1858, 107, p. 254) by the action of ammonia on glyoxal, 2C2H2O2 + 2NH3 = C3H4N2 + H2CO2 + 2H2O. The compounds of this series may be prepared by the condensation of ortho-diketones with ammonia and aldehydes