Saint Augustine

354-430

1. Italian philosopher, influenced the development of Western philosophy and Western Christianity 
2. Doctrine of original sin: Man is by nature ‘sinful’, as he is product of ‘original sin’(sin of Adam and Eve). He cannot escape from Sin.
3. Just war theory: right conduct in war" (Jus In Bello) and “justification to go to war" (Jus Ad Bellum)
4. Founding father of Christianity;
5. He made distinction between "City of God" and "City of Man";
6. If justice taken away, state becomes band of robbers;

Work:

1. The City of God - 426 AD; divided into 22 books;
2. On Christian Doctrine
3. Confessions. 

Thomas Aquinas

1225-1274

1. Theological (religious) views on politics 
2. Gave 5 proof of ‘existence of God’ 
3. Happiness is contemplation of God 
4. God is source of reason, wisdom, virtue, and happiness 
5. But these virtues (reason, wisdom, etc) can be acquired by anyone, in any culture, any religion
6. Gave theory of just war: ordered by legitimate authority( the sovereign), just cause, to promote good and to avoid evil 
7. wrote several important commentaries on Aristotle's works 
8. Division of labor, individual autonomy, against slavery 
9. Monarchy best form of govt/Constitution Book: Summa Theologica
10. He gave the hierarchy of law.

Books:

1. On Being and Essence 
2. Summa Theologica

Marsilio of Padua

(1275 – 1342)

1. Important 14th-century Italian political thinker 
2. Book: Defensor Pacis (The Defender of Peace)- which supported separation of temporal power ( king) from spiritual power( church) 
3. Hence, he is considered to have propounded Medieval Secularism