O período entre o fechamento da escola de Atenas a mando de Justiniano em 529 e o Inicio do renascimento Carolíngeo (+- 787) é bem "trevoso"
Por exemplo, é digna de nota a escassez de nomes importantes na filosofia, matemática e ciência em geral neste período.
O intervalo que compreende o Sec X, que vai do fim do renascimento carolíngeo até os tempos de Sto Anselmo e Abelardo
(o chamado renascimento do Sec XII) também é meio sombrio.
Óbvio que estou me restringindo a europa.
Ainda assim, algumas figuras interessantes, mas bem obscuras, viveram nestas épocas
Por exemplo, o chamado "Agostinho Irlandês" (Augustinus Hibernicus)
Da wikipedia:
...
Around the year 655 he wrote a treatise called De mirabilibus sacrae scripturae. It has long been regarded as an exceptional work, in that it demonstrates a strictly scientific approach in the matter of making direct observations of nature and subjecting them to a strictly logical interpretation.
His treatise seeks to explain each miracle in the Scriptures as an extreme case of phenomena, yet still within the laws of nature. Augustine also gives a list of the terrestrial mammals of Ireland, and solves the problem of how they reached Ireland after the flood of Noah by proposing a solution – hundreds of years ahead of its time – that the island had been cut off from continental Europe by marine erosion.
...
E tambem Gerberto de Aurillac (Papa Silvestre II) c.946-1003
...
Gerbert was said to be one of the most noted scientists of his time. Gerbert wrote a series of works dealing with matters of the quadrivium (arithmetic, geometry, astronomy, music), which he taught using the basis of the trivium (grammar, logic, and rhetoric). In Rheims, he constructed a hydraulic-powered organ with brass pipes that excelled all previously known instruments,[16] where the air had to be pumped manually. In a letter of 984, Gerbert asks Lupitus of Barcelona for a book on astrology and astronomy, two terms historian S. Jim Tester says Gerbert used synonymously.[17] Gerbert may have been the author of a description of the astrolabe that was edited by Hermannus Contractus some 50 years later
...
E acho uma pena que não se ensine mais lógica, retórica, astronomia e musica nas escolas.