Gennadius Scholarius
| Gennadius II of Constantinople | |
|---|---|
| Ecumenical Patriarch of Constantinople | |
| Gennadius II of Constantinople on a wall fresco in a monastery in Serres | |
| Church | Church of Constantinople | 
| In office | 6 January 1454 – 6 January 1456 April 1463 – June 1463 Autumn 1464 – autumn 1465 | 
| Predecessor | Athanasius II of Constantinople Joasaph I of Constantinople Sophronius I of Constantinople | 
| Successor | Isidore II of Constantinople Sophronius I of Constantinople Mark II of Constantinople | 
| Personal details | |
| Born | Georgios Kourtesios c. 1400 | 
| Died | c. 1472 Saint John Prodromos Monastery near Siroz, Rumelia Eyalet, Ottoman Empire | 
| Sainthood | |
| Feast day | 25 August | 
| Venerated in | Eastern Orthodox Church | 
Gennadius II of Constantinople (Greek: Γεννάδιος; lay name: Γεώργιος Κουρτέσιος Σχολάριος, Georgios Kourtesios; c. 1400 – c. 1472) was a Byzantine Greek philosopher and theologian, and Ecumenical Patriarch of Constantinople from 1454 to 1465. He was a strong advocate for the use of Aristotelian philosophy in the Orthodox Church.
Gennadius II was, together with his mentor, Mark of Ephesus, involved in the Council of Florence which aimed to end the schism between the Orthodox and Catholic churches. Gennadius II had studied and written extensively on Catholic theology. After the failure of the union of Florence and the Fall of Constantinople, Gennadius II became the first Ecumenical Patriarch of Constantinople under Ottoman rule. Just before the fall of Constantinople, and after Cardinal Isidore of Kiev had celebrated a Latin Mass in Hagia Sophia to celebrate the ratification of the Council of Florence, its citizens consulted Gennadius II. Gibbon has him say: "O miserable Romans, why will ye abandon the truth? and why, instead of confiding in God, will ye put your trust in the Italians? In losing your faith you will lose your city. Have mercy on me, O Lord! I protest in thy presence that I am innocent of the crime. O miserable Romans, consider, pause, and repent. At the same moment that you renounce the religion of your fathers, by embracing impiety, you submit to a foreign servitude".
A polemicist, Gennadius II left in writing several treatises on the differences between Catholic and Orthodox theology, the Filioque, a defence of Aristotelianism and excerpts from an exposition (entitled Confession) of the Eastern Orthodox faith addressed to Mehmed II.