Ptolemy Quotes
All the men who are now called discoverers, in every matter ruled by thought, have been men versed in the minds of their predecessors, and learned in what had been before them. There is not one exception. I do not say that every man has made direct acquantance with the whole of his mental ancestry... But... it is remarkable how many of the greatest names in all departments of knowledge have been real antiquaries in their several subjects.
I may cite among those... in science, Aristotle, Plato, Ptolemy, Euclid, Archimedes, Roger Bacon, Copernicus, Francis Bacon, Ramus, Tycho Brahe, Galileo, Napier, Descartes, Leibnitz, Newton, Locke.
Augustus De Morgan
Not much younger than these (sc. Hermotimus of Colophon and Philippus of Mende) is Euclid, who put together the Elements, collecting many of Eudoxus' theorems, perfecting many of Theaetetus', and also bringing to irrefragable demonstration the things which were only somewhat loosely proved by his predecessors. This man lived in the time of the first Ptolemy. For Archimedes, who came immediately after the first (Ptolemy), makes mention of Euclid: and, further, they say that Ptolemy once asked him if there was in geometry any shorter way than that of the elements, and he answered that there was no royal road to geometry. He is then younger than pupils of Plato but older than Eratosthenes and Archimedes; for the latter were contemporary with one another, as Eratosthenes somewhere says.
Proclus
Thus the Empire of the Greeks, which at first brake into four kingdoms, became now reduced into two notable ones, henceforward called by Daniel the kings of the South and North. For Ptolemy now reigned over Egypt, Lybia, Ethiopia, Arabia, Phœnicia, Cœlosyria, and Cyprus; and Seleucus, having united three of the four kingdoms, had a dominion scarce inferior to that of the Persian Empire, conquered by Alexander the great. All which is thus represented by Daniel: And the king of the South [Ptolemy] shall be strong, and one of his Princes [Seleucus, one of Alexander's Princes] shall be strong above him, and have dominion; his dominion shall be a great dominion.
Isaac Newton