Karl Rahner was influenced by many people to study Christian philosophy and theology and to be apart of the society of Jesus and to be a Jesuit. He was influenced by Saint Thomas Aquinas, Saint Augustine, Martin Heidegger, Immanuel Kant, Joseph Maréchal and Neo-Thomism. Karl was apart of the 20th century philosophy era, he is considered one of the most influential Catholic theologians of the 20th century.