and error even when complete truth could not be obtained. This is the course pursued by Plato in his earlier dialogues; but in the ThecBtetus the Platonic Socrates asks the prof ounder question : ' ' What is knowledge ? ' ' It is not sensation, for sensation alone gives us no objective certainty. It is not opinion, for opinion may or may not be true. A man only knows when he sees the reasons or causes of things; when he perceives facts as links in the chain of cause and effect. Man can only know that he knows, when he deals with that which is permanent and universal. What then is this? Plato's answer is found in his theory of ideas or forms. These are not material objects, but the everlasting essences, to be apprehended only by the reason; they are the substances of which material things are but the shadow. In our time they are generally described as mental concepts. The form of a statue is not the marble out of which it is carved, but the thought or conception of the sculptor, of which the marble is only an expression. In his Republic Plato elaborates his theory of knowledge and gives an illustration of it by picturing a majority of mankind as prisoners in a subterranean cavern chained with their backs to a fire, looking at the shadows thrown by it on the rocky wall and mistaking them for realities. The turning around of these prisoners to the light, their toilsome ascent up the steep slope to the mouth of the cave, the gradual training of their eyes to see the real things in the upper world and then finally looking up to the sun itself all represent the education of the philosopher. Education is turning around the eye of the soul to the light. Learning, according to the Meno and Phœ-drus, is recollecting; the soul in a previous existence has beheld the ideas or forms ; and knowledge is possible because the mind does not acquire something alien to it but recovers what is its own.

Philosophy to Plato was not mere intellectual speculation, but a habit of mind and a manner of living. The highest of the ideas in his view was the good. While he does not accept the theory that pleasure is the good, neither does he agree with the cynics that all pleasure is evil. Pleasures are good or bad, high or low, according to the part of the soul to which they belong Plato accepts without proof the popular distinction of four cardinal virtues: wisdom, the virtue of reason; courage, the virtue of the spirited element; temperance (i. e., moderation, self-control in general), the virtue of the lower parts in their relation to the higher; and justice, the virtue of the whole soul.

In Plato's Timœus the cosmos or order of the universe is the "one only begotten image of God," its father and creator. The Creator, being good, wished to make the world as nearly like Himself as possible; but

no created or visible thing can be perfect. The material out of which the world was formed introduced evil into it. So also the Creator could not make the world eternal like Himself, and He therefore created time, "the moving image of eternity." See Professor Jowett's translation of Plato. The doctrine of immortality is the main subject of the Phcedo, and as the soul, according to Plato's philosophy, had an existence before the body, it cannot be affected by the death and dissolution of the body.

Piatt'deutsch' (plăht doitsh) or Low Qer= man, the direct descendant of Old Saxon, is spoken to-day in different dialects by the peasantry of northern Germany from the Rhine to Pomerania. Low German softens the consonants, but avoids the deep sibilants of high German as spoken in the south, and has simple grammatical rules. It is very appropriate in the mouths of the people who use it, their chief characteristics being a childlike good nature and sturdy honesty. Klaus Groth, Fritz Reuter (a. v.) and other writers have given it a high literary standing.

Platte (or Nebras'ka), a tributary of Missouri River, is formed by the junction of its northern and southern forks in western Nebraska. These forks, which rise among the Rocky Mountains in Colorado, are 800 and 500 miles long, respectively, but neither is navigable. The general direction of the Platte is eastward in a wide, shallow stream over the plains of Nebraska till it reaches the Missouri after a winding course of over 400 miles. With its forks it drains 300,000 square miles of territory, but is not navigable.

Platts'burg, N. Y., a village and the county-seat of Clinton County, is famous for two naval battles of the War of T812, in the latter of which the American flotilla was completely victorious. The village is situated upon Lake Champlain, and is the port of entry of the Champlain customs-district. It thus is an important center of trade with Canada. Plattsburg is a garrison town, a summer resort and the seat of manufactures in iron, wood, wool, flour and sewing machines. Population 11,138.

Plautus (plaw'tus), Titus Maccius, the chief comedian of Rome, was born about 254 B. C. in Sarsina, a village in Umbria. We have no positive knowledge as to his early life and education, but it is probable that he came to Rome at an early age and there acquired his mastery of the most idiomatic Latin. At Rome he found employment in connection with the stage, and made money enough to set up in business for himself in the way of foreign trade. He, however, failed in business and returned to Rome in such poverty that he was compelled to earn his livelihood by turning a handmill, work usually performed by slaves. While engaged in this occupationj he wrote three plays,