But, it is not so easy in other cases to know exactly what to say and think. For example, there is the case of Pascal's niece, Marguerite Perrier, who had long suffered from a serious, disfiguring "lachrymal fistula" in the corner of her eye. On March 24, 1656 she was healed through being touched by a Holy Thorn that had recently been presented to the Sisters of Port-Royal. The healing of Mlle. Perrier was substantiated by medical evidence and because Port-Royal was a center of Jansenist influence -- a movement that sought to return Catholic practice to the theology of Augustine -- and which was, at that time, being persecuted by the Roman authorities, it was natural for them to see the Lord authenticating their cause with this miracle and others that followed it, a cause we Calvinist Presbyterians would like to think had been accredited by God. This miracle caused Pascal to begin collecting materials for his Defense of Christianity, which was to be entitled Apology for the Christian Religion, but which was never published. His notes for it which he had collected before his premature death at the age of 39 were later published under the title Pensees, or "Thoughts."