became the seat of a Christian bishopric about the middle of the 10th century. The original settlement was on the right bank of the Warthe, but the new town, established on the opposite bank by German settlers about 1250, soon became the more important part of the double city. Posen became a great depot for the trade between Germany and western Europe on the one hand and Poland and Russia on the other. Many foreign merchants made the city their residence, and these included a colony of Scots, who exported produce to Edinburgh. The city attained the climax of its prosperity in the 16th century, when its population, according to one estimate, reached 80,000. The intolerance shown to the Protestants, the troubles of the Thirty Years' War, the plague and other causes, soon conspired to change this state of affairs, and in the 18th century the population sank to 12,000. New life was infused into the city after its annexation by Prussia at the second partition of Poland in 1 793, and since this date its growth has been rapid. See Lukaszewicz, Histofisch-statistisches Bild der Stadt Posen 968-1793 (Ger. trans., Posen, 1881); Ohlenschlager, Kurzgefassle Gesch-ichte und Beschreibung der Stadt Posen (Posen, 1886); Narschauer, Stadtbuch mm Posen (Posen, 1892); and Fiihrer durch Posen (Poscn, 1895).
POSIDIPPUS (grd cent. B.C.), Greek dramatist, of Cassandrea in Macedonia, the last and one of the most distinguished of the writers of the new comedy. He began to write for the stage in 289 B.C., and, according to Suidas, wrote 40 plays, of which I7 titles and some fragments have been preserved. He appears to have gone somewhat out of the beaten track in his choice of subjects, and it is evident that cooks held an important position in his list of characters. His comedies were frequently imitated by the Romans (Aulus Gellius ii. 23), and it is considered very probable that the M enaechmi (a comedy of errors) of Plautus is an adaptation either from the "O, U-OLOL, or from some unknown comedy of Posidippus, called Aibv/iot, or perhaps Mévottxpon. His statue in the Vatican is considered a masterpiece of ancient art.
Fragments in A. Meineke, Poetafum comicorum graccorum fragment (1855).
POSIDIPPUS is also the name of a writer of epigrams (c. 270 B.c.), of which about 30 are preserved in the Greek Anthology. See W. Christ, Griechtsche Lilteraturgeschichte (1898).
POSIDONIUS (c. 130-50 B.C.), nicknamed “ the Athlete, ” Stoic philosopher, the most learned man of his time' (so Strabo TLTW Ka.l9' 'Fl/.tcis q5L}o06¢wv 1ro)w;w.0éo'TaTos, Galen é1rur1'17/.Lol/u<<l>1'a1'oS) and perhaps of all the school. A native of Apamea in Syria and a pupil of Panaetius, he spent after his teacher's death many years in travel and scientific researches in Spain (particularly at Gades), Africa, Italy, Gaul, Liguria, Sicily and on the eastern shores of the Adriatic. When he settled as a teacher at Rhodes (hence his surname “ the Rhodian ”) his fame attracted numerous scholars; next to Panaetius he did most, by writings and personal intercourse, to spread Stoicism in the Roman world, and he became well known to many leading men, such as Marius, Rutilius Rufus, Pompey and Cicero. The last-named studied under him (78-77 B.c.), and speaks as his admirer and friend. He visited Rome, e.g. on an embassy in 86 B.C., but probably did not settle there as a teacher.,
His works, now lost, were written in an attractive style and proved a mine of information to later writers. The titles and subjectsiof more than twenty of them are known. In common with other Stoics of the middle period, he displayed eclectic tendencies, following the older Stoics, Panaetius, Plato and Aristotle. Hisadmiration for Plato led him to write a commentary on the Timaeus; in another way it is shown by important modifications which he made in psychological doctrine. Unquestionably more of a polymath than a philosopher, he appears uncritical and superficial. But at the time his spirit of inquiry provoked Strabo's criticism as something alien to the school (ni U.f.TLOA0'Yl.K6V Kai 'ro 6.p1.a'1'o1'é)l.§ 'o1/, iivrep éKKA£1/OUULV oi 15,211-rpm). In natural science, geography, natural history, mathematics and astronomy he took a genuine interest. He sought to determine the distance and magnitude of the sun, to calculate the diameter of the earth and the influence of the moon on the tides. His history of the period from 146 to 88 B.C., in fifty-two books, must have been a valuable storehouse of facts. Cicero, who submitted to his criticism the memoirs which he had written in Greek of his consulship, made use of writings of Posidonius in De natura deorum, bk. ii., and De dtvinatione, bk. i., and the author of the pseudo-Aristotelian treatise De mundo also borrowed from him.
See Zeller, Philosophie der Griechen, iii. 1, 570-584 (in Eng. trans., Ectectictsm, 56-70); C. Muller, Fra.g11zenta historicorum graecomm, iii. 245-296; ]. Bake, Posidonii Rhodii reliquiae (Leiden, 1810), a valuable monograph; R. Scheppig, De Posidzmio rerum gentfium terramm scripture (Berlin, 1869); R. Hirzel, Untersuchungen zu Ciceros philosophischevt Schnften, i. 191 seq., ii. 257 seq., 325 seq., 477-535, 756-789, iii. 342-378 (Leipzig, 1877); Thiaucourt, Essai sur les traités plztlosophigues de Cicéron (Paris, 1885); Schmekel, Die Philosophie der mitttem Stoa (1892); Arnold, Untersuchungen 12ber Theophanes von Myttlene und Posidonius von Apamea, (1882). (See also Srorcs.)
POSITIVE (or PORTABLE) ORGAN, a medieval chamber organ which could be carried from place to place without being taken to pieces, and when played was placed on a table or stool and required a blower for the bellows, as well as a performer. It was larger and more cumbersome than the portative (q.v.), with which it has often been confounded. The positive had usually but one kind of pipe, the open diapason of 2 ft. tone, and in the 16th century the best types had three registers by means of which each note could be sounded with its fifth and octave, or each by itself, or again in combinations of twos. The positive differed from the regal in having flue pipes, whereas the latter had beating reeds in tiny pipes, one or two inches long, concealed behind the keyboard. During the early middle ages most of the pneumatic organs belonged to this type.
A well-known instance of an early positive or portable organ of the 4th century occurs on the Obelisk erected to the memory of Theodosius the Great, on his death in A.D. 395. Among the illuminated manuscripts of the British Museum miniatures abound representing interesting varieties of the portable organ of the middle ages; such as Add. MS. 29902 (fol. 6) and Add. MS. 27695b (fol. 13), Cotton MS. Tiberius A VII. fol. 1o4d., all of the 14th century, Add. MS. 28962, Add. MS. 17280, both of the 15th century. These little organs were to be found at every kind of function, civil and religious; they were used in the dwellings and Chapels of the rich; at banquets and court functions; in choirs and music schools; and in the small orchestras of Peri and Monteverdi at the dawn of the musical drama or opera. (K. S.)
POSITIVISM (derived from ponere, whence posttus, that which is laid down, certain), a philosophical term, applied somewhat loosely to any system which confines itself to the data of experience and declines to recognize a priori or metaphysical speculations. In this sense the term may be applied to empirical philosophers in general. Thus Hume is a positivist in the sense that he specifical ly restricts philosophy to the sphere of observation, and regards the causal relation as being nothing more than what we have been accustomed to expect. Similarly Mill, Spencer and physical scientists generally view the universe from the positivist standpoint. In its commonest acceptation, however, positivism is both narrower and Wider than this. The term is specifically used of the philosophy of Auguste Comte, who applied the term to his system according to which knowledge is based exclusively on the methods and discoveries of the physical or “ positive ” sciences. According to Comte human thought passes through three stages-theological, metaphysical and positive. The final stage, positivism, is the understanding of the universe not as composed of a multitude of individuals each with volition, but as an ordered organism governed by necessary laws (see further COMTE). The outcome of this positivism is the substitution for revealed religion of a religion of humanity-according to Huxley “ Catholicism minus Christianity ”—in which God is replaced by Humanity. This religion was to have its special priesthood, ritual and organization. Positivism has, therefore, two distinct sides, the philosophical and the religious or mystical. Philosophical positivism has had distinguished representatives in France, Germany and England, and in the wider sense indicated above may be regarded as one of the two or three chief influences on modern philosophical development. Though the details of Comte's philosophic structure, e.g. the classification of the sciences, are without important significance, the positivistic tendency is prominent in all systems of thought which den the supernatural and the metaphysical. Agnosticism, Phenomenafi ism, Rationalism, Materialism all manifest the positivist spirit, denying what may be succinctly described as the met empirical.