DELUSION is an erroneous belief, usually rather persistent and more elaborate in character than hallucinations or illusions, inasmuch as it is commonly based on more or less elaborate, if fallacious, reasoning. Delusions may result from ignorance or prejudice, or they may be due to mental abnormality, known as "delusional insanity." In the most serious cases they are confined to a few subjects such as persecution or personal eminence, etc.
ABNORMAL PSYCHOLOGY; HALLUCINATION; ILLUSION. DELYANNI, THEODOROS (1826-19o5), Greek states man, was born at Kalavryta, Peloponnesus, in 1826. He studied law at Athens, and entered the civil service. In 1862, he became minister for foreign affairs. In 1867 he was minister at Paris. In the so-called "Oecumenical Ministry" of 1877 he voted for war with Turkey, and on its fall he entered the cabinet of Koumoundoros as minister for foreign affairs. He was a repre sentative of Greece at the Berlin congress in 1878. From this time forward, and particularly after 1882, when Tricoupi again came into power at the head of a strong party, the duel between these two statesmen was the leading feature of Greek politics. (See GREECE: History.) Delyanni first formed a cabinet in 1885; but his warlike policy ended in failure. He returned to power in 189o, with a radical programme, but his failure to deal with the financial crisis produced a conflict between him and the king, and his disrespectful attitude resulted in his summary dismissal in 1892. In 1895, however, he again became prime minister, and was at the head of affairs during the Cretan crisis and the opening of the war with Turkey in 1897. The humiliating defeat which ensued—though Delyanni himself had been led into the disastrous war policy to some extent against his will—caused his fall in April 1897, the king again dismissing him from office when he declined to resign. Delyanni kept his own seat at the election of 1899, but his following dwindled to small dimensions. He was again president of the council and minister of the interior when, on June 13, 19o5, he was murdered in revenge for the rigorous measures taken by him against gambling houses.
