which neither the high reputation that he acquired by the reestablishment of the declining empire of Rome, nor his general moderation of character and love of justice, have been able to wipe out. This persecution, which commenced in the spring of 303, was the most dreadful that the Roman church ever suffered, and in memory of it, the year in which Diocletian was nominated to the empire was for ages known in christian chronology as the era of the martyrs.—W. M.
DIODATI, Jean, a, learned divine, born at Geneva in 1576, of a family originally from Italy, and died in 1649. On the recommendation of Beza he was appointed professor of Hebrew in the university of Geneva, when he was only twenty-one years of age. In 1608 he was made pastor or parish minister, and in 1609 professor of theology. He was a bold and fearless preacher, and suffered no regard to worldly considerations to hamper him in the somewhat difficult duties which were then attached to the Geneva pulpit. Diodati was highly esteemed by the clergy of his native city, who sent him on a mission, first to the reformed churches of France, and afterwards to those of Holland. On the latter occasion he attended the synod of Dort, and was one of the divines appointed to draw up the acts of that assembly, he was besides an industrious writer. He published both an Italian and a French translation of the Bible; "Annotationes in Biblia;" "De Ecclesia;" "De Antichristo;" and a considerable number of other controversial works.—R. M., A.
DIODORUS CHRONUS, flourished about 300 b.c.; a citizen of Iasus in Caria; a friend of Ptolemy Soter, who is reported to have given him his surname on occasion of his hesitation when called upon to solve some of the riddles of Stilpo. His death is attributed to his vexation at his defeat. According to another account, he himself adopted the name of Chronus from that of his teacher Apollonius. Diodorus was one of those philosophers who combined the Eleatic metaphysics (see Parmenides) with the dialectics of the Megarean school He himself dealt more with logical forms than the à priori principles on which they were founded, and has handed down the results of his speculation in a set of argumentative dicta, which find their common ground and connection in the abstract conception of Absolute Unity. Regarding the universe not as the manifestation of physical relations, but the visible record of the laws of thought, he was led to attribute to it the same rigid necessity which characterizes them. Hence his identification of the real with the possible expressed in the "argumentum dominans." "Nothing," he held, "is possible which neither is nor will be true," because the necessity of the past implies the necessity of the future. Past and future are parts of one scheme. In the same light we must regard his view of the reciprocal connection of the two members of a hypothetical proposition. He maintained that the antecedent depended upon the consequent as much as the consequent on the antecedent, because, in the universe, every event was dependent on every other. He denied the divisibility of space and the reality of motion; making use of Zeno's argument, that at any given moment a body said to be in motion is at rest, and that a succession of rests no more make up motion than a series of points make up a line. The obvious answer to this has been often missed. We only assert motion in time, and time is not made up of a succession of infinitesimal, but of definite moments. Herophilus the surgeon, tried to answer Diodorus in another way less logical but more forcible, when he refused to complete the setting of the philosopher's dislocated shoulder, on the ground that he was convinced by this reasoning that he could not move it. In so far as his speculations assumed a physical form, they approached those of Democritus. While affirming that the universe was one whole, he yet admitted that it was made up of a number of invisible atoms, ruled by unchangeable laws. His great fame was as a logician; Cicero styles him "valens dialecticus," and Sextus praises still more higher his subtlety in argument. He is one of those thinkers whose thought we study as an exercise of our own, and not to learn anything positive from its results.—J. N.
DIODORUS the Sicilian, commonly styled Diodorus Siculus, a contemporary of Cicero and Augustus, was born in the town of Agyrium in Sicily. Of the history of his life nothing is known except what is to be gathered from his own works. He appears early to have formed the design of writing a universal history from the earliest down to his own times. In accordance with this design, he travelled for some years in Europe and Asia, correcting by local research the accounts of historians and geographers. He lived also a long time at Rome, where he found abundance of valuable materials for his work. He spent in all thirty years upon this great undertaking. It embraced the history of all ages and countries, and so in a manner supplied the place of a whole library; whence he called it Βιβλιοθήκη, or, as Eusebius (Præparatio Evangelica i. 6) says, Βιβλιοθήκη ἱστορικη. Scaliger, in his Animadversiones ad Eusebium, renders it highly probable that Diodorus wrote his work after the year 8 b.c., when Augustus corrected the calendar. Diodorus mentions Cæsar's invasion of Britain, and also his death and apotheosis. The Βιβλιοθήκη consists of forty books, and comprehends a period of one thousand one bundled and thirty-eight years, besides the time preceding the Trojan war. There is also another division of the work into three sections. The first comprises the first six books, and contains the history of the mythical times previous to the war with Troy. The following eleven books constitute the second section, and bring the history down to the time of the death of Alexander the Great. The third, consisting of the remaining twenty-three books, closes with the Gallic war and conquest of Britain. Of the forty books of this great history only fifteen have come down to us complete, namely, books i. to v., and xi. to xx. But a considerable number of fragments of the lost books have been gathered together out of writers by whom Diodorus has been quoted. The work is written in the form of annals, the events of each year being related in purely chronological order. Diodorus made diligent use of all sources of information which were accessible to him, and, had he possessed sound critical powers in any considerable degree, might have produced a history of great value. But he has only made an extensive compilation. Whatever he found in his authorities he set down in perfect good faith—history, mythus, and fiction are thus frequently jumbled together. He often misunderstands his author, and although he professes to have paid particular attention to chronology, his dates are not seldom obviously incorrect. The Spanish Vives called him a mere trifler, and Bodin accuses him of ignorance and carelessness. He has, however, found defenders amongst eminent critics, and it is unquestionable that we are indebted to him for much important and reliable information which escaped the notice of all other historians. Nor should it be forgotten that probably the most valuable part of his work has been lost. Even by the fragments that remain, many of the errors of Livy have been corrected. Whenever Diodorus speaks from personal observation he may be relied on; it is therefore the more to be regretted that in some instances, as in the account of Egypt, it is impossible to say whether he is speaking as an eye-witness or upon the report of others. His style is on the whole clear and lucid, but characterized by considerable inequalities, as indeed might be expected in the work of a compiler. The dialect in which he wrote is said to hold the middle between the archaic or refined attic, and the vulgar Greek that was spoken in his time. The history of Diodorus was first published in Latin translations. P. Wesseling's edition, which has an extensive and very valuable commentary, was published at Amsterdam in 1746, 2 vols., folio. The best modern edition is that of L. Dindorf, Leipzig, 1828, 6 vols., 8vo. Dindorf also edited in a separate volume the new fragments which had been discovered by A. Mai.—R. M., A.
DIOGENES of Apollonia, though a Cretan by birth, may be called the last philosopher of the Ionic school. Flourishing in the fifth century, he was a contemporary of Anaxagoras, and shared with him, on the occasion of a visit to Athens, the honour or dishonour of rendering himself obnoxious to the defenders of religion in his age. Looking at nature from a point of view partly physical, partly speculative, he revived the doctrine of Anaximenes, that air is the first principle of things. His dim notion of a first cause had not assumed the form of Pure Reason, but was a sort of Corporeal Intelligence, in the conception of which he confused mental and bodily attributes. All things in his view were one, made out of one principle; not the abstract one of the Eleatics, but something that the plant had in common with the soil, by virtue of which the one grew out of the other. This was air—in a higher than the ordinary sense—a purer air than was ever seen by mortals, largior æther. Phenomenal forms were self-changing modes of its action. It exhibited various degrees of warmth and density, and adapted itself in different forms to diverse phases of being. According to the cosmogony of Diogenes, the earth, condensed by cold, is fixed in the centre of the world; out of it living creatures are formed. The lighter
