Euclid's Elements of Geometry, Plane and Solid

We arrive, therefore, at length at Plato, to whom no other brought greater splendor than he did to the Mathematical disciplines. He amplified Geometry with the greatest accessions, having placed incredible study into it. And primarily, Analysis was discovered by him, the most certain way of finding and reasoning. He distinguished the books of his philosophy with Mathematical reasons, and he roused whatever was admirable in Mathematics when joined with philosophy. At the doors of his Academy was written: οὐδεὶς ἀγεωμέτρητος εἰσίτω: let no one lacking in Geometry enter: an illustrious argument, indeed, of how Mathematics is not alien to, but proper to, and not useless or unbecoming, but honest and fitting for, sound and certain Philosophy. How great an admirer and cultivator of Mathematics Plato was, he will at last understand who has read through his monuments.

From Plato’s Academy, almost innumerable mathematicians subsequently emerged. Thirteen companions of Plato are commemorated by Proclus, by whose studies Mathematics was made absolute. Hence Leodamas of Thasos, Archytas of Tarentum, and Theaetetus of Athens; by whom the mathematical arts were egregiously amplified. Leodamas practiced the Analysis received from Plato, and by its help, he is said by Laertius to have discovered many things. Theaetetus is made illustrious both by his own inventions, among which the Elements written by him and the inscription of regular solids are celebrated, and by the encomiums of Plato, who even inscribed a dialogue with his name.