Synesius was a member of a well-known and rich family of Cyrene, which claimed descent from the half-legendary founders of the city, members of the Spartan royal house. His family's wealth enabled him and his brother Euoptius to travel to Greece (before 392) and study in Alexandria (after 393), where Hypatia introduced them to Neo-Platonism. This philosophy taught that there was one, supreme God, that everything in the universe was in harmony (or "sympathy", as it was called), and that God cared for Creation (providence).
Synesius would never cease to believe this, and always remained friends with the wise woman, with whom he continued to exchange lettersnote when he retired to his estate Anchimachus,
studying philosophy, mathematics, astronomy, everything; farming, hunting, having many a brush with hordes of pilfering Libyans; and every now and then upholding the cause of someone who had undeservedly fallen into difficulties
- in short, the life of a Greek or Roman gentleman.
In these years, he composed several texts, which show that he was a talented writer. His Greek is usually an excellent Attic, but his hymns - lighthearted and majestic at the same time - are composed in good Dorian. In these hymns, he praises the beauty of the universe. Unlike many of his contemporaries, he does not treat the subject in a pedantic way. One of his works is On Dreams, which are, in his view, divine revelations that a good philosopher can understand; they are a way to "become linked with the spheres, that is to say, be carried up as if to its own natural state of being", and reach the origin of our existence without having to perform rituals or visit the temples (which had been closed in 392). His treatise On Dog Breeding is now lost. A trip from Alexandria to Cyrene, during which he survived shipwreck, is commemorated in a boyish Letter 4.
In 397, he visited the emperor Arcadius in Constantinople, to whom he offered aurum coronarium (crown gold). He also wanted to petition for lower taxes for his native city, which had suffered from tribal invaders. It took some time before he caught the emperor's ear, but when he was allowed to speak, he spoke out clearly: his speech On Imperial Rule contains of course all the usual topical statements about the role of a philosopher as impartial and disinterested adviser of a ruler, but also a bold statement that the ruler must act against the abuse of power and corruption, and send away the Germanic troops. This was a very relevant topic, as a Germanic leader named Gainas had almost overthrown the state in 399-400.note
Having achieved his aim, Synesius went home. On the day of his departure, there was an earthquake.note He visited the Academy of Athens, which he found, in comparison to the philosophical school of Hypatia, disappointing. He found the ancient city
like a victim burnt in the sacrificial fire: there remains nothing but the skin to help us to reconstruct a creature that was once alive".note
Synesius' speech In Praise of Baldness suggests that he was initiated in the Eleusinian Mysteries as well, which were - at that time - falling into decay.note (It is possible that he visited Athens during the three years in Constantinople.)
He visited Alexandria again, where he married a Christian wife, whose name is not revealed in his letters, but for whom he wrote Hymn 8, which contains many Christian motifs. The ceremony was presided over by bishop Theophilus, patriarch of Alexandria. Clearly, Synesius was not greatly perturbed by the religious differences. This attitude is illustrated in his Letter 154, to Hypatia, in which he mocks Christian philosophers and empty, pagan sophistry, and states that he wants to adhere to the real truth that reveals itself in several ways. The couple had several children, who were born in Alexandria.
After some time, they traveled to Cyrene, but did not enjoy their stay: war broke out and Synesius was to command small armies, which he had recruited and financed himself.note At an unknown moment before 407, his estate was overran, and he had to move to the city.
In spite of this, in general, there were happy moments as well, often dedicated to literary activities, farming, and hunting. His letters show that Synesius was torn between two sentiments: on the one hand, a passion for the quiet life on his country estatenote with his books, for which he even sold part of his landnote and on the other hand his responsibility for his city and his people.note
Among the publications of this period are a treatise On an Astrolabe that he constructed for a friend in Constantinople, an amusing speech In Praise of Baldness (a reply to In Praise of Hair by Dio Chrysostom). He also published an essay On Dio Chrysostom, a late first-century sophist-philosopher like Synesius, who uses this essay to explain his cultural ideal. His main work in these years, however, was The Egyptian Tale, or On Providence, published in 402 It is a romanticized account of his trip to Constantinople, in which two of Arcadius' ministers are likened to the Egyptian gods Osiris and Seth.