354-430 algeria augustine autobiography bekering biographies biography bishopofhippo bishops catholicchurch christianlife christianliterature christiansaints développement early earlychristianphilosophy earlyworksto1800 faith foi general goodandevil grâce(théologie) hippo(extinctcity) history louangededieu medieval ouvragesavant1800 philosophy saint saints saintschrétiens spirituallife surveys theology