Edith Stein (religious name Teresa Benedicta a Cruce OCD; also known as St. Teresa Benedicta of the Cross; 12 October 1891 – 9 August 1942), was a German Jewish philosopher who converted to Roman Catholicism and became a Discalced Carmelite nun. She is canonized as a martyr and saint of the Catholic Church.

She was born into an observant Jewish family, but was an atheist by her teenage years. Moved by the tragedies of World War I, in 1915 she took lessons to become a nursing assistant and worked in an infectious diseases hospital. After completing her doctoral thesis from the University of Göttingen in 1916, she obtained an assistantship at the University of Freiburg.

From reading the works of the reformer of the Carmelite Order, Teresa of Ávila, she was drawn to the Catholic faith. She was baptized on 1 January 1922 into the Roman Catholic Church. At that point, she wanted to become a Discalced Carmelite nun, but was dissuaded by her spiritual mentors. She then taught at a Catholic school of education in Speyer. As a result of the requirement of an "Aryan certificate" for civil servants promulgated by the Nazi government in April 1933 as part of its Law for the Restoration of the Professional Civil Service, she had to quit her teaching position.

She was admitted to the Discalced Carmelite monastery in Cologne the following October. She received the religious habit of the Order as a novice in April 1934, taking the religious name Teresa Benedicta of the Cross. In 1938, she and her sister Rosa, by then also a convert and an extern sister (tertiaries of the Order, who would handle the community′s needs outside the monastery), were sent to the Carmelite monastery in Echt, Netherlands, for their safety. Despite the Nazi invasion of that state in 1940, they remained undisturbed until they were arrested by the Nazis on 2 August 1942 and sent to the Auschwitz concentration camp, where they died in the gas chamber on 9 August 1942.

① Introduction：The Inquiry into Being

1.Preliminary Discussion of St. Thomas Aquinas'doctrine of Act and Potency

2.The Problem of Being in History

3.Linguistic Difficulies

4.Is there a Christian Philosophy？

②、act and potency as modes of being

③、essential and actual being

④、essentia（ousia，wesen）—substance—form and matter

⑤、existents as such（the transcendentals）

⑥、the meaning of being

⑦、the image of the trinity in the created world