How did Augustine and Thomas Aquinas contribute to medieval thinking?

Augustine was one of the greatest writers from the early middle ages. his writing were mainly theological and devotional, but some were philosophical as well. augustine lived much of his life as a sinner, but in his 30s he converted to christianity and later became bishop of north africa. in a poem to god, augustine told of his conversion for all to hear. he explained that the city of god was not an earthly kingdom, but a heavenly one.aquinas joined the dominicans, but didnt partake in dominican practices well. he was also fat and had slow speech, uncharacteristic of dominicans. after reading aristotles works, aquinas decided to show in a systematic and scientific way that god existed and that christianity was correct. his work was known as the summa theologica, a textbook for college students.