Author
- Innocent I1
- Innocent III1
- Isidore of Seville1
- Jacobus de Burgo1
- Jacomo Veronese1
- Jacques Legrand1
- James of Lausanne1
- Jerome1
- Johannes Nider1
- Johannis Hieronymus1
- John Koukouzeles1
- John Versor1
- John Zonaras1
- John of Damascus1
- Leontius of Costantinople1
- Nemesius1
- Nicholas III of Constantinople1
- Nicoluccio di Ascoli1
- Nikifor Venyukov1
- Nilus of Constantinople1