Elements

Euclid's Elements is a primary mathematical text whose logical method, definitions, postulates and propositions built one upon another, has been checked and rechecked by mathematicians for over two thousand years, which is the real basis for treating it as authoritative rather than any claim about its modern publisher. This record cites it specifically for Book I's definitions, its third postulate and Proposition 1, and for the scholium to Book XIII crediting the cube, pyramid and dodecahedron to the Pythagoreans and the octahedron and icosahedron to Theaetetus, a documented internal attribution within the text itself. As a primary text it is authoritative for what Euclid himself states or what the text's own scholium attributes; a claim about the actual historical priority of these geometric discoveries beyond what the text itself says needs a dedicated history of Greek mathematics.