Saint Augustine, also known as Augustine of Hippo, was a Christian philosopher and the founder of Neo-Platonism. He was born in North Africa in 354. Saint Augustine believed and taught that humans are "rational soul[s] making use of a mortal and material body" (43). Later in life he returned to North Africa where he became the Bishop of Hippo. He died there in 430 (Collinson & Plant, 2006).
Saint Anslem was an Italian philosopher and archbishop of Canterbury who lived from about 1033 to 1109. He is known for his ontological argument on the existence of god ("Saint Anslem of Canterbury", 2016).
David Hume was a Scottish philosopher who lived from 1711 to 1777. Hume believed that all human thought was generated through human senses. He was an empiricist who argued that humans cannot know whether or not God exists or what is "right" because these matters cannot be learned through the use of human senses (Collinson & Plant, 2006).
Collinson, D. & Plant, K. (2006). Fifty major philosophers. (2nd ed.). New York, NY: Routledge.
Saint Anselm of Canterbury. (2016). In Encyclopædia Britannica. Retrieved from http://www.britannica.com/biography/Saint-Anselm-of-Canterbury