Proclus: A Commentary on the First Book of Euclid's Elements

according angles equal appears Aristotle assume axioms Barocius base bounded called cause character circle clear commentary common conclusion constructed contained converse definition demonstration diameter direction distance divided divisible draw drawn Elements equal equal to angle equilateral Euclid evident example existence extended fall figures follows forms four Friedlein geometer geometry given greater Heath Hence hypothesis ideas imagination impossible intelligible interior angles joined kind knowledge later length less Limit magnitude mathematics matter means meet method moving namely nature objects opposite parallel parallelogram philosophy plane Plato position possible postulate present principles problem Proclus produced proof properties propositions proved Reading reason reference remaining respectively right angles sense sides simple solid soul square straight line surface taken term theorem things thought tion triangle understanding unequal universal whole