Iamblichus' Life of Pythagoras

Pythagoras was considered to be a being of this kind, through whom a correct conception—conformable to reality—was introduced regarding gods, heroes, and spirits; regarding the world, the varied motion of the spheres and stars, their oppositions, eclipses, and irregularities, their eccentricities and epicycles; and regarding all natures contained in the heavens and the earth, together with those that have an intermediate existence, whether apparent or hidden. There was nothing in this information contrary to physical phenomena or intellectual concepts.

Furthermore, all such disciplines, theories, and scientific investigations—which truly invigorate the eye of the soul and purify the intellect from the blindness introduced by other studies, enabling it to perceive the true principles and causes of the universe—were unfolded by Pythagoras to the Greeks. Beyond this, the best political system, public harmony, community of possessions among friends, the worship of the gods, piety toward the dead, legislation, education, silence, abstinence from animal meat, continence, temperance, wisdom, and, in one word, whatever is anxiously sought after by lovers of learning, was brought to light by Pythagoras. For all these reasons, therefore, as I have just said, he was universally and transcendently admired.

CHAP. VII.

It remains for us to relate how he traveled, what places he first visited, what discourses he gave, on what subjects, and to whom they were addressed; for in this way, we shall easily understand the nature of his interaction with the people of that time.