Author
- Peter Olivi1
- Peter of Poitiers1
- Petrus de Monastero1
- Pietro de' Crescenzi1
- Placentinus1
- Porphyry1
- Pseudo Bernard of Clairvaux1
- Pseudo-Andronicus of Rhodes1
- Pseudo-Cicero1
- Ralph of Longchamp1
- Ramon Llull1
- Republic of Venice1
- Richard Maidstone1
- Richard Rolle1
- Richard of Middleton1
- Robert Gazeley1
- Robert Holkot1
- Robert Kilwardby1
- Robert de Sorbon1
- Roman Catholic Archdiocese of Siena1