identity of indiscernibles Principle enunciated by G.W. Leibniz that denies the possibility of two objects being numerically distinct while sharing all their non-relational properties in common, where a relational
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926 I identity theory ► Ignatyev
property is one that involves bearing a relation to another object. More formally, the principle states that if x is not identical to y, then there is some non-relational property P such that P holds of x and does not hold of y, or that P holds of y and does not hold of x. Equivalently, if x and y share all their non-relational properties, then x is identical to y. Its con¬ verse, the principle of the indiscemibility of identicals (also known as Leibniz’s Law), asserts that if x is identical to y, then every non-relational property of x is a property of y, and vice versa.
identity theory In the philosophy of mind, the doctrine that mental events are identical to physico-chemical events in the brain. So-called “type” identity theory asserts that each type of mental event, such as pain, is identical to some type of event in the brain, such as the firing of c-fibres. In response to objections based on the assumed “multiple realizability” of mental states, “token” identity theory makes the weaker claim that each token of a mental event, such as a particular pain, is identical to some token of a brain event of some type. See also mind-body problem.
ideology Form of social or political philosophy in which practical ele¬ ments are as prominent as theoretical ones. The term was coined in 1796 by the French writer Antoine-Louis-Claude, Comte Destutt de Tracy (b. 1754—d. 1836), as a label for his “science of ideas.” Certain character¬ istics of his thought proved generally true of ideologies, including a more or less comprehensive theory of society, a political program, anticipation of a struggle to implement that program (thus requiring committed fol¬ lowers), and intellectual leadership. Destutt de Tracy’s ideas were adopted by the French Revolutionary government in building its version of a democratic, rational, and scientific society (see Directory). Napoleon first gave the term a negative connotation with his scorn for what he called ideologues. Ideology is often contrasted unfavourably with pragmatism. The significance of ideology follows from the fact that power is rarely exercised without some ideas or beliefs that justify support.
Iditarod \,I- , dit-3- l rad\ Trail Sled Dog Race U.S. dogsled race. It is held each March and run over a route between Anchorage and Nome, Alaska. It originated in 1967 as a race 56 mi (90 km) long, but by 1973 it had evolved into the current race, a 1,152-mi (1,855-km) trek roughly tracing an old mail route established in 1910. The race also commemo¬ rates an emergency mission to get medical supplies to Nome during a diphtheria epidemic in 1925. It typically takes 9-14 days to complete the race. See also dogsled racing.
idol Image or statue of a deity used as an object of worship. In Judaism, the making of any representation of God is strictly forbidden, as is the fash¬ ioning of any “graven image.” Islam has also adhered to this rule. In Chris¬ tianity, there has been a general acceptance of pictorial or sculpted images of Jesus and the saints and, on occasion, God, and Christianity has thus always faced the danger that such representations could be venerated superstitiously as idols. In Jainism, Hinduism, and Buddhism images of gods and saints are common; they are often the object of veneration. In Hin¬ duism, a statue may be treated as a god as an act of devotion but loses its special status when the act of devotion is finished (see Durga-puja, puja).
Idris \id-'res\ I in full SIdl Muhammad Idris al-Mahdl al-SanusT (b. March 13, 1890, Jarabub, Cyrenaica, Libya—d. May 25, 1983, Cairo, Egypt) King of Libya (1951-69). He succeeded his father in 1902 as leader of Cyrenaica but did not rule in his own name until 1916. Negotiations with Italy, which held the Libyan coast, resulted in agree¬ ments that confirmed Idris’s authority (1917) and established a parliament (1919). His refusal to disarm his tribal supporters, however, led to Italy’s invasion of Tripolitania in 1922, and Idris went into exile until after World War II (1939—45). In 1949 Cyrenaica and the other two Libyan provinces united under a constitutional monarchy headed by Idris. Independence was declared in 1951. He was overthrown by Col. Muammar al-Qaddafi in a military coup in 1969.
Idrlsid \'id-ri-sid\ dynasty Arab Muslim dynasty that ruled Berber areas of Morocco (789-921). The founder, Idris I (r. 789-791), established the shariflan tradition in Morocco, by which the claim to descent from Muhammad was established as the principle for monarchic rule. His son Idris II (r. 803-828) founded Fez (modern Fes) in 808. The dynasty was the first to incorporate both Berbers and Arabs. It broke up into rival prin¬ cipalities, paving the way for another Berber group, the Almoravid dynasty.
idyll or idyl Vl-dal, 'i-dal\ In literature, a simple descriptive work in poetry or prose that deals with rustic life or pastoral scenes or suggests a mood of peace and contentment. Idylls have taken varying forms, from
the eclogue to the long narrative poem treating an epic, romantic, or tragic theme (such as Alfred Tennyson’s “Idylls of the King”).
Ifat \i-'fat\ (1285-1415) Muslim state, central Ethiopia. Flourishing in the fertile uplands, it was established through the conquests of a 13th-century ruler known as Walashma. It served as a buffer between the kingdom of Damot and the Christian kingdom of Ethiopia. Ifat was conquered by the Ethiopian king Amda Tseyon in 1328 and made tributary to Ethiopia. After a long series of revolts, it was destroyed in 1415 when it was annexed to Ethiopia.
Ifni \'if-ne\ Region, southwestern Morocco. Located on the coast of the Atlantic Ocean, it has an area of some 580 sq mi (1500 sq km). It was settled in 1476 by Diego Garcia de Herrera, lord of the Canaries, as a Spanish fishing, slaving, and trading locality. Abandoned in 1524 because of disease and the hostility of the local population, Spain reclaimed it fol¬ lowing a treaty with Morocco in 1860. Effective Spanish reoccupation began in 1934, and it became part of Spanish West Africa in 1946. Ifni was ceded to Morocco in 1969.
IG Farben World’s largest chemical cartel from its founding in Germany until its dissolution by the Allies after World War II. It grew out of a com¬ plex merger of German manufacturers of chemicals, pharmaceuticals, and dyestuffs {Farben). Its major members were the companies known today as BASF AG, Bayer AG, Hoechst AG, Agfa-Gevaert Group, and Cassella AG. They formed a loose association in 1916 and were formally united in 1925, with headquarters in Frankfurt. IG Farben expanded internationally in the late 1920s and the 1930s. During World War II, it established a synthetic oil and rubber plant at Auschwitz to take advantage of slave labour by the death camp’s inmates, on whom it also conducted drug experiments. After the war, several company officials were convicted of war crimes, and IG Farben was broken up into three independent companies.
Igbo \'ig-bo\ or Ibo Ve-bo\ People of southeastern Nigeria. The Igbo speak dialects of Igbo, a Benue-Congo language of the Niger-Congo fam¬ ily (see Niger-Congo languages). Before European colonization the Igbo lived in autonomous local communities, but by the mid 20th century they had developed a strong sense of ethnic identity. During conflicts in 1966 many Igbo in northern Nigeria were killed or forced into their traditional homelands in the east. In 1967 the Eastern region tried to secede from Nigeria as the independent nation of Biafra; hundreds of thousands of Igbo were killed or died of starvation. Today they number some 20 million. Many are farmers, but trading, crafts, and wage labour are also important, and many have become civil servants and business entrepreneurs.