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CHAP. VII.
His Inventions.
HE added much to learning and language by many inventi∣ons, as well of things as of words. To omit Dialectick, of which we treated last,a 1.1 Phavorinus attributes to his invention, discoursing by way of Question; but Aristotle ascribes it to Alexame∣nus, a Styrian or Teian, and it appears by the Dialogues of Plato, that Socrates also used that form of arguing. Laertius informes us, that Zeno Ele••tes was the first composer of Dialogues; yet in my opinion, saith he, Pla••o hath so much refined the form thereof, that he deserves to be preferr'd before all others, as well for invention as reformation.
More properly may be attributed to him the invention ofb 1.2 Ana∣lyticall Method, which reduceth the thing sought unto its principle, the best of Methods. He taught it to Leodamas, and by it found out ma∣ny things in Geometry: Analysis, as defined by thec 1.3 Scholiast up∣on Euclid, is a sumption of the thing sought, by the consequents, (as if it were already known) to find out the truth. Examples thereof we find in the five first propositions of the 13t• Book of Euclid, besides se∣verall others, that occurre in Apollonius Pergaeus, and Pappus Alexandrinus.
Amongst his Geometricall Inventions also must be remembred the duplication of a Cube, the occasion and manner whereof is rela∣ted byd 1.4 Plutarch ande 1.5 Philoponus. The Delians afflicted with the Pestilence, consulted the Oracle of Apollo; he answer'd, the Plague would cease if they doubled their•• Altar, which was of a Cubick figure. Plu••arch saith, that hereupon the Overseers of the Altar made all the four sides double to what they were before, & so in∣stead of doubling the Altar, they made it octuple to what it was. Philoponus saith, they caused another Cube of the same bignesse with the former to be set upon it, whereby they changed the fi∣gure of the Altar, which was no longer a Cube, but 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, a qua∣drilaterall Pillar. The first way, it was Cubicall, but not double, the second way double, but not Cubicall. The Plague not cea∣sing, they consulted the Oracle again. Apollo answer'd, they had not fulfilled his Command, which was to build a Cubicall Al∣tar as big again as the former. Hereupon they went to Plato, as most skilfull in Geometry, to learn of him the Oracle's meaning, and how they should find out the way of doubling a Cube, re∣taining the Cubick figure. Plato answered, that the God mocked the Grecians for their neglect of Philosophy and Learning, in∣sulting over their ignorance, that he commanded them seri∣ously, to addict themselves to Geometry, that this could not be done any other way, then by finding out two mean proportio∣nalls between two right lines in a Duple proportion (Plato's par∣ticular